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Ball (mathematics)

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31: 52: 1000: 691: 2632: 995:{\displaystyle {\begin{aligned}V_{2k}(r)&={\frac {\pi ^{k}}{k!}}r^{2k}\,,\\V_{2k+1}(r)&={\frac {2^{k+1}\pi ^{k}}{\left(2k+1\right)!!}}r^{2k+1}={\frac {2\left(k!\right)\left(4\pi \right)^{k}}{\left(2k+1\right)!}}r^{2k+1}\,.\end{aligned}}} 2400: 666: 2905: 2425: 1622: 696: 1237: 1350: 1696: 1777: 2246: 569: 436: 403: 1490: 2820: 2668: 1944: 1888: 2815: 2122: 1980: 1530: 2241: 1848: 1819: 2180: 350: 323: 2148: 2420: 2080: 2060: 2040: 2020: 2000: 1716: 1095: 370: 296: 2954:. Note this theorem does not hold if "open" subset is replaced by "closed" subset, because the origin point qualifies but does not define a norm on  688:
at the integers and half integers gives formulas for the volume of a Euclidean ball that do not require an evaluation of the gamma function. These are:
2627:{\displaystyle B(r)=\left\{x\in \mathbb {R} ^{n}\,:\left\|x\right\|_{p}=\left(|x_{1}|^{p}+|x_{2}|^{p}+\dots +|x_{n}|^{p}\right)^{1/p}<r\right\}.} 685: 1535: 1158: 1271: 69: 3282: 135: 3268: 116: 88: 73: 3395: 3346: 95: 3192: 1631: 1725: 102: 62: 3083: 3438: 408: 375: 2719:-norm, known as the Euclidean metric, generates the well known disks within circles, and for other values of 84: 3217: 3098: 1450: 3004: 498: 1375: 252: 2644: 3365: 3315: 1893: 1068: 3393:
Gruber, Peter M. (1982). "Isometries of the space of convex bodies contained in a Euclidean ball".
3227: 2395:{\displaystyle \left\|x\right\|_{p}=\left(|x_{1}|^{p}+|x_{2}|^{p}+\dots +|x_{n}|^{p}\right)^{1/p},} 1858: 1399: 545: 661:{\displaystyle V_{n}(r)={\frac {\pi ^{\frac {n}{2}}}{\Gamma \left({\frac {n}{2}}+1\right)}}r^{n},} 3412: 3381: 3355: 3332: 3181: 2941: 2703: 1493: 1433: 1379: 510: 263: 232: 1867: 2794: 2088: 3448: 3278: 3144: 2969: 2900:{\displaystyle \lVert x\rVert _{\infty }=\max\{\left|x_{1}\right|,\dots ,\left|x_{n}\right|\}} 1949: 1499: 1429: 109: 2220: 1824: 1782: 3443: 3404: 3373: 3324: 3136: 2915: 2681: 1387: 1005: 2153: 328: 301: 3160: 3152: 2196: 1719: 1425: 1414: 240: 228: 186: 175: 35: 2127: 3369: 2184:
The Euclidean balls discussed earlier are an example of balls in a normed vector space.
3433: 2778: 2405: 2065: 2045: 2025: 2005: 1985: 1701: 1391: 1080: 677: 673: 355: 281: 157: 3427: 3416: 3385: 3377: 3164:, bounded by two planes passing through a sphere center and the surface of the sphere 3128: 3102: 2724: 1395: 1417:
if, given any positive radius, it is covered by finitely many balls of that radius.
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can be classified in two classes, that can be identified with the two possible
3236: 2927: 1403: 1260:, is likewise defined as the set of points of distance less than or equal to 3274: 3025: 1383: 1367: 681: 1374:
A ball in a general metric space need not be round. For example, a ball in
17: 3222: 3208: 3203: 2923: 275: 248: 217: 1617:{\displaystyle B_{r}(p)\subseteq {\overline {B_{r}(p)}}\subseteq B_{r},} 3408: 3360: 3336: 3313:
Smith, D. J.; Vamanamurthy, M. K. (1989). "How small is a unit ball?".
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where the balls are all translated and uniformly scaled copies of 
1143:, is defined the same way as a Euclidean ball, as the set of points in 3197: 3140:, bounded by a conical boundary with apex at the center of the sphere 3118: 2205: 526: 515: 244: 236: 162: 1402:
is never compact. However, a ball in a vector space will always be
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Dowker, J. S. (1996). "Robin Conditions on the Euclidean ball".
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function to fractional arguments). Using explicit formulas for
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of open balls. This topology on a metric space is called the
2975:, not necessarily induced by a metric. An (open or closed) 478:
is the set of all points of distance less than or equal to
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parallel to the coordinate axes as their boundaries. The
1398:. For example, a closed ball in any infinite-dimensional 185:
These concepts are defined not only in three-dimensional
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parallel to the coordinate axes; those according to the
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A number of special regions can be defined for a ball:
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In particular, a ball (open or closed) always includes
3156:, bounded by two concentric spheres of differing radii 2823: 2797: 2647: 2428: 2408: 2249: 2223: 2156: 2130: 2091: 2068: 2048: 2028: 2008: 1988: 1952: 1896: 1870: 1827: 1785: 1728: 1704: 1634: 1538: 1502: 1453: 1274: 1161: 1083: 694: 572: 411: 378: 358: 331: 304: 284: 1232:{\displaystyle B_{r}(p)=\{x\in M\mid d(x,p)<r\}.} 1532:in this topology. While it is always the case that 76:. Unsourced material may be challenged and removed. 2899: 2809: 2662: 2626: 2414: 2394: 2235: 2174: 2142: 2116: 2074: 2054: 2034: 2014: 1994: 1974: 1938: 1882: 1842: 1813: 1771: 1710: 1690: 1616: 1524: 1484: 1345:{\displaystyle B_{r}=\{x\in M\mid d(x,p)\leq r\}.} 1344: 1231: 1089: 994: 660: 554:-dimensional volume of a Euclidean ball of radius 430: 397: 364: 344: 317: 290: 189:but also for lower and higher dimensions, and for 2843: 2402:Then an open ball around the origin with radius 1004:In the formula for odd-dimensional volumes, the 680:(which can be thought of as an extension of the 2746:- balls are within octahedra with axes-aligned 2723:, the corresponding balls are areas bounded by 462:is the set of all points of distance less than 3299:NIST Digital Library of Mathematical Functions 3018:-ball is homeomorphic to the Cartesian space 1691:{\displaystyle {\overline {B_{r}(p)}}=B_{r}.} 1406:as a consequence of the triangle inequality. 1099:be a positive real number. The open (metric) 8: 2894: 2846: 2831: 2824: 1930: 1918: 1877: 1871: 1772:{\displaystyle {\overline {B_{1}(p)}}=\{p\}} 1766: 1760: 1336: 1297: 1223: 1184: 2759:-balls are within cubes with axes-aligned 2689:metric) are bounded by squares with their 1432:, the open sets of which are all possible 1413:if it is contained in some ball. A set is 3359: 2884: 2857: 2834: 2822: 2796: 2654: 2650: 2649: 2646: 2600: 2596: 2585: 2580: 2573: 2564: 2549: 2544: 2537: 2528: 2519: 2514: 2507: 2498: 2483: 2467: 2461: 2457: 2456: 2427: 2407: 2379: 2375: 2364: 2359: 2352: 2343: 2328: 2323: 2316: 2307: 2298: 2293: 2286: 2277: 2262: 2248: 2222: 2155: 2129: 2096: 2090: 2067: 2047: 2027: 2007: 1987: 1957: 1951: 1895: 1869: 1826: 1790: 1784: 1736: 1729: 1727: 1703: 1670: 1642: 1635: 1633: 1596: 1568: 1561: 1543: 1537: 1507: 1501: 1461: 1454: 1452: 1279: 1273: 1166: 1160: 1082: 984: 969: 929: 890: 872: 829: 813: 806: 775: 763: 754: 734: 728: 703: 695: 693: 649: 621: 601: 595: 577: 571: 431:{\displaystyle \operatorname {int} D^{n}} 422: 410: 398:{\displaystyle \operatorname {int} B^{n}} 389: 377: 357: 336: 330: 309: 303: 283: 136:Learn how and when to remove this message 1371:(open or closed) is a ball of radius 1. 3259: 1890:is also a metric space with the metric 686:particular values of the gamma function 3270:Encyclopedic Dictionary of Mathematics 3148:, bounded by a pair of parallel planes 2788:generates the inner of usual spheres. 1485:{\displaystyle {\overline {B_{r}(p)}}} 1358:itself, since the definition requires 298:-dimensional ball is often denoted as 3068:. The homeomorphisms between an open 7: 3043:-ball is homeomorphic to the closed 2791:Often can also consider the case of 74:adding citations to reliable sources 493:-space, every ball is bounded by a 227:. Thus, for example, a ball in the 3101:; if it is smooth, it need not be 2835: 2804: 2763:, and the boundaries of balls for 1946:In such spaces, an arbitrary ball 613: 178:that constitute the sphere) or an 25: 2995:to an (open or closed) Euclidean 2727:(hypoellipses or hyperellipses). 1394:. A closed ball also need not be 1245:(metric) ball, sometimes denoted 566:-dimensional Euclidean space is: 42:is the volume bounded by a sphere 3189:, an extension to negative radii 2968:One may talk about balls in any 2706:metric, have squares with their 2663:{\displaystyle \mathbb {R} ^{2}} 50: 27:Volume space bounded by a sphere 1939:{\displaystyle d(x,y)=\|x-y\|.} 1698:For example, in a metric space 61:needs additional citations for 3329:10.1080/0025570x.1989.11977419 2581: 2565: 2545: 2529: 2515: 2499: 2479: 2473: 2438: 2432: 2360: 2344: 2324: 2308: 2294: 2278: 2258: 2252: 2166: 2160: 2108: 2102: 2042:may be viewed as a scaled (by 1969: 1963: 1912: 1900: 1802: 1796: 1748: 1742: 1682: 1676: 1654: 1648: 1608: 1602: 1580: 1574: 1555: 1549: 1519: 1513: 1473: 1467: 1409:A subset of a metric space is 1327: 1315: 1291: 1285: 1214: 1202: 1178: 1172: 796: 790: 718: 712: 589: 583: 262:In other contexts, such as in 1: 3396:Israel Journal of Mathematics 3347:Classical and Quantum Gravity 2022:with a distance of less than 3304:Release 1.0.6 of 2013-05-06. 3054:-ball is homeomorphic to an 3007:, as the building blocks of 1752: 1658: 1584: 1477: 1015:is defined for odd integers 243:, a ball is taken to be the 3200:, a similar geometric shape 3193:Neighbourhood (mathematics) 2670:, "balls" according to the 2641:, in a 2-dimensional plane 2217:, that is one chooses some 2124:Such "centered" balls with 1029:+ 1)!! = 1 ⋅ 3 ⋅ 5 ⋅ ⋯ ⋅ (2 3465: 3378:10.1088/0264-9381/13/4/003 3116: 2914:More generally, given any 1883:{\displaystyle \|\cdot \|} 543: 270:is sometimes used to mean 3039:. Any closed topological 2810:{\displaystyle p=\infty } 2117:{\displaystyle B_{1}(0).} 497:. The ball is a bounded 3267:Sūgakkai, Nihon (1993). 3084:topological orientations 3003:-balls are important in 2817:in which case we define 2679:-norm (often called the 1975:{\displaystyle B_{r}(y)} 1525:{\displaystyle B_{r}(p)} 1043:In general metric spaces 235:, the area bounded by a 3218:Alexander horned sphere 2702:-norm, also called the 2236:{\displaystyle p\geq 1} 1853:In normed vector spaces 1843:{\displaystyle p\in X.} 1814:{\displaystyle B_{1}=X} 1386:, and a ball under the 231:is the same thing as a 201:dimensions is called a 85:"Ball" mathematics 3132:, bounded by one plane 3005:combinatorial topology 2901: 2811: 2664: 2628: 2416: 2396: 2237: 2176: 2144: 2118: 2076: 2056: 2036: 2016: 1996: 1976: 1940: 1884: 1844: 1815: 1773: 1712: 1692: 1618: 1526: 1486: 1428:, giving this space a 1346: 1233: 1147:of distance less than 1091: 996: 662: 525:, and is bounded by a 432: 399: 366: 346: 319: 292: 166:; it is also called a 43: 3058:-ball if and only if 3014:Any open topological 2964:In topological spaces 2902: 2812: 2665: 2629: 2417: 2397: 2238: 2177: 2175:{\displaystyle B(r).} 2145: 2119: 2077: 2062:) and translated (by 2057: 2037: 2017: 1997: 1977: 1941: 1885: 1845: 1816: 1774: 1713: 1693: 1628:always the case that 1619: 1527: 1487: 1376:real coordinate space 1347: 1234: 1114:, usually denoted by 1092: 997: 663: 433: 400: 372:-dimensional ball is 367: 347: 345:{\displaystyle D^{n}} 320: 318:{\displaystyle B^{n}} 293: 253:one-dimensional space 33: 3316:Mathematics Magazine 2821: 2795: 2645: 2426: 2422:is given by the set 2406: 2247: 2221: 2154: 2128: 2089: 2066: 2046: 2026: 2006: 1986: 1950: 1894: 1868: 1825: 1783: 1726: 1702: 1632: 1536: 1500: 1451: 1420:The open balls of a 1272: 1159: 1106:centered at a point 1081: 1071:(distance function) 692: 570: 409: 376: 356: 329: 302: 282: 249:2-dimensional sphere 212:and is bounded by a 70:improve this article 3370:1996CQGra..13..585D 2999:-ball. Topological 2940:, one can define a 2916:centrally symmetric 2910:General convex norm 2143:{\displaystyle y=0} 1859:normed vector space 1438:topology induced by 1400:normed vector space 546:Volume of an n-ball 3409:10.1007/BF02761407 3239:– a 3-ball in the 3182:Disk (mathematics) 3178:– ordinary meaning 3097:-ball need not be 2897: 2807: 2660: 2624: 2412: 2392: 2233: 2172: 2140: 2114: 2072: 2052: 2032: 2012: 1992: 1972: 1936: 1880: 1840: 1811: 1769: 1708: 1688: 1614: 1522: 1482: 1380:Chebyshev distance 1342: 1229: 1087: 992: 990: 658: 450:-space, an (open) 442:In Euclidean space 428: 395: 362: 342: 315: 288: 274:. In the field of 266:and informal use, 264:Euclidean geometry 182:(excluding them). 44: 3297:Equation 5.19.4, 3119:Spherical regions 2987:is any subset of 2970:topological space 2415:{\displaystyle r} 2150:are denoted with 2075:{\displaystyle y} 2055:{\displaystyle r} 2035:{\displaystyle r} 2015:{\displaystyle y} 1995:{\displaystyle x} 1755: 1711:{\displaystyle X} 1661: 1587: 1496:of the open ball 1480: 1090:{\displaystyle r} 963: 866: 748: 643: 629: 609: 365:{\displaystyle n} 291:{\displaystyle n} 241:Euclidean 3-space 146: 145: 138: 120: 16:(Redirected from 3456: 3420: 3389: 3363: 3340: 3305: 3295: 3289: 3288: 3264: 3247: 3231: 3214:, or hypersphere 3211: 3108: 3096: 3089: 3081: 3075: 3071: 3067: 3057: 3053: 3046: 3042: 3038: 3029: 3024:and to the open 3023: 3017: 3002: 2998: 2990: 2986: 2981:topological ball 2978: 2974: 2959: 2953: 2949: 2939: 2933: 2906: 2904: 2903: 2898: 2893: 2889: 2888: 2866: 2862: 2861: 2839: 2838: 2816: 2814: 2813: 2808: 2787: 2776: 2769: 2758: 2745: 2736: 2722: 2718: 2701: 2678: 2669: 2667: 2666: 2661: 2659: 2658: 2653: 2640: 2633: 2631: 2630: 2625: 2620: 2616: 2609: 2608: 2604: 2595: 2591: 2590: 2589: 2584: 2578: 2577: 2568: 2554: 2553: 2548: 2542: 2541: 2532: 2524: 2523: 2518: 2512: 2511: 2502: 2488: 2487: 2482: 2466: 2465: 2460: 2421: 2419: 2418: 2413: 2401: 2399: 2398: 2393: 2388: 2387: 2383: 2374: 2370: 2369: 2368: 2363: 2357: 2356: 2347: 2333: 2332: 2327: 2321: 2320: 2311: 2303: 2302: 2297: 2291: 2290: 2281: 2267: 2266: 2261: 2242: 2240: 2239: 2234: 2216: 2208: 2203: 2190: 2181: 2179: 2178: 2173: 2149: 2147: 2146: 2141: 2123: 2121: 2120: 2115: 2101: 2100: 2081: 2079: 2078: 2073: 2061: 2059: 2058: 2053: 2041: 2039: 2038: 2033: 2021: 2019: 2018: 2013: 2001: 1999: 1998: 1993: 1981: 1979: 1978: 1973: 1962: 1961: 1945: 1943: 1942: 1937: 1889: 1887: 1886: 1881: 1863: 1849: 1847: 1846: 1841: 1820: 1818: 1817: 1812: 1795: 1794: 1778: 1776: 1775: 1770: 1756: 1751: 1741: 1740: 1730: 1717: 1715: 1714: 1709: 1697: 1695: 1694: 1689: 1675: 1674: 1662: 1657: 1647: 1646: 1636: 1623: 1621: 1620: 1615: 1601: 1600: 1588: 1583: 1573: 1572: 1562: 1548: 1547: 1531: 1529: 1528: 1523: 1512: 1511: 1491: 1489: 1488: 1483: 1481: 1476: 1466: 1465: 1455: 1443: 1388:taxicab distance 1364: 1357: 1351: 1349: 1348: 1343: 1284: 1283: 1267: 1263: 1259: 1253: 1238: 1236: 1235: 1230: 1171: 1170: 1154: 1150: 1146: 1142: 1127: 1113: 1109: 1105: 1098: 1096: 1094: 1093: 1088: 1074: 1066: 1058: 1038: 1022: 1014: 1006:double factorial 1001: 999: 998: 993: 991: 983: 982: 964: 962: 958: 954: 935: 934: 933: 928: 924: 911: 907: 891: 886: 885: 867: 865: 858: 854: 835: 834: 833: 824: 823: 807: 789: 788: 762: 761: 749: 747: 739: 738: 729: 711: 710: 671: 667: 665: 664: 659: 654: 653: 644: 642: 641: 637: 630: 622: 611: 610: 602: 596: 582: 581: 565: 559: 553: 535: 524: 507: 492: 485: 481: 477: 474:-ball of radius 473: 469: 465: 461: 457: 454:-ball of radius 453: 449: 437: 435: 434: 429: 427: 426: 404: 402: 401: 396: 394: 393: 371: 369: 368: 363: 351: 349: 348: 343: 341: 340: 324: 322: 321: 316: 314: 313: 297: 295: 294: 289: 224: 209: 200: 141: 134: 130: 127: 121: 119: 78: 54: 46: 21: 3464: 3463: 3459: 3458: 3457: 3455: 3454: 3453: 3439:Metric geometry 3424: 3423: 3392: 3343: 3312: 3309: 3308: 3296: 3292: 3285: 3266: 3265: 3261: 3256: 3251: 3246: 3240: 3229: 3209: 3171: 3121: 3115: 3106: 3105:to a Euclidean 3094: 3087: 3077: 3073: 3069: 3059: 3055: 3051: 3044: 3040: 3033: 3027: 3019: 3015: 3000: 2996: 2988: 2984: 2976: 2972: 2966: 2955: 2951: 2945: 2935: 2931: 2912: 2880: 2876: 2853: 2849: 2830: 2819: 2818: 2793: 2792: 2782: 2779:superellipsoids 2771: 2768: 2764: 2757: 2751: 2744: 2738: 2731: 2720: 2717: 2711: 2700: 2694: 2677: 2671: 2648: 2643: 2642: 2635: 2579: 2569: 2543: 2533: 2513: 2503: 2497: 2493: 2492: 2472: 2471: 2455: 2448: 2444: 2424: 2423: 2404: 2403: 2358: 2348: 2322: 2312: 2292: 2282: 2276: 2272: 2271: 2251: 2250: 2245: 2244: 2219: 2218: 2215: 2211: 2206: 2199: 2197:Cartesian space 2193: 2188: 2152: 2151: 2126: 2125: 2092: 2087: 2086: 2064: 2063: 2044: 2043: 2024: 2023: 2004: 2003: 2002:around a point 1984: 1983: 1953: 1948: 1947: 1892: 1891: 1866: 1865: 1861: 1855: 1823: 1822: 1786: 1781: 1780: 1732: 1731: 1724: 1723: 1720:discrete metric 1700: 1699: 1666: 1638: 1637: 1630: 1629: 1592: 1564: 1563: 1539: 1534: 1533: 1503: 1498: 1497: 1457: 1456: 1449: 1448: 1441: 1424:can serve as a 1415:totally bounded 1359: 1355: 1275: 1270: 1269: 1265: 1261: 1255: 1251: 1246: 1162: 1157: 1156: 1152: 1148: 1144: 1129: 1120: 1115: 1111: 1107: 1103: 1079: 1078: 1076: 1072: 1064: 1063:, namely a set 1048: 1045: 1024: 1016: 1008: 989: 988: 965: 941: 937: 936: 917: 913: 912: 900: 896: 892: 868: 841: 837: 836: 825: 809: 808: 799: 771: 768: 767: 750: 740: 730: 721: 699: 690: 689: 669: 645: 620: 616: 612: 597: 573: 568: 567: 561: 555: 551: 548: 542: 530: 519: 502: 490: 483: 479: 475: 471: 467: 463: 459: 455: 451: 447: 444: 418: 407: 406: 385: 374: 373: 354: 353: 352:while the open 332: 327: 326: 305: 300: 299: 280: 279: 229:Euclidean plane 219: 207: 198: 187:Euclidean space 176:boundary points 174:(including the 142: 131: 125: 122: 79: 77: 67: 55: 36:Euclidean space 28: 23: 22: 15: 12: 11: 5: 3462: 3460: 3452: 3451: 3446: 3441: 3436: 3426: 3425: 3422: 3421: 3403:(4): 277–283. 3390: 3361:hep-th/9506042 3354:(4): 585–610. 3341: 3323:(2): 101–107. 3307: 3306: 3290: 3283: 3258: 3257: 3255: 3252: 3250: 3249: 3244: 3234: 3225: 3220: 3215: 3206: 3201: 3195: 3190: 3184: 3179: 3172: 3170: 3167: 3166: 3165: 3157: 3149: 3141: 3133: 3114: 3111: 3093:A topological 3009:cell complexes 2965: 2962: 2911: 2908: 2896: 2892: 2887: 2883: 2879: 2875: 2872: 2869: 2865: 2860: 2856: 2852: 2848: 2845: 2842: 2837: 2833: 2829: 2826: 2806: 2803: 2800: 2766: 2755: 2748:body diagonals 2742: 2715: 2698: 2675: 2657: 2652: 2623: 2619: 2615: 2612: 2607: 2603: 2599: 2594: 2588: 2583: 2576: 2572: 2567: 2563: 2560: 2557: 2552: 2547: 2540: 2536: 2531: 2527: 2522: 2517: 2510: 2506: 2501: 2496: 2491: 2486: 2481: 2478: 2475: 2470: 2464: 2459: 2454: 2451: 2447: 2443: 2440: 2437: 2434: 2431: 2411: 2391: 2386: 2382: 2378: 2373: 2367: 2362: 2355: 2351: 2346: 2342: 2339: 2336: 2331: 2326: 2319: 2315: 2310: 2306: 2301: 2296: 2289: 2285: 2280: 2275: 2270: 2265: 2260: 2257: 2254: 2232: 2229: 2226: 2213: 2192: 2186: 2171: 2168: 2165: 2162: 2159: 2139: 2136: 2133: 2113: 2110: 2107: 2104: 2099: 2095: 2071: 2051: 2031: 2011: 1991: 1971: 1968: 1965: 1960: 1956: 1935: 1932: 1929: 1926: 1923: 1920: 1917: 1914: 1911: 1908: 1905: 1902: 1899: 1879: 1876: 1873: 1854: 1851: 1839: 1836: 1833: 1830: 1810: 1807: 1804: 1801: 1798: 1793: 1789: 1768: 1765: 1762: 1759: 1754: 1750: 1747: 1744: 1739: 1735: 1707: 1687: 1684: 1681: 1678: 1673: 1669: 1665: 1660: 1656: 1653: 1650: 1645: 1641: 1627: 1613: 1610: 1607: 1604: 1599: 1595: 1591: 1586: 1582: 1579: 1576: 1571: 1567: 1560: 1557: 1554: 1551: 1546: 1542: 1521: 1518: 1515: 1510: 1506: 1479: 1475: 1472: 1469: 1464: 1460: 1392:cross-polytope 1341: 1338: 1335: 1332: 1329: 1326: 1323: 1320: 1317: 1314: 1311: 1308: 1305: 1302: 1299: 1296: 1293: 1290: 1287: 1282: 1278: 1249: 1228: 1225: 1222: 1219: 1216: 1213: 1210: 1207: 1204: 1201: 1198: 1195: 1192: 1189: 1186: 1183: 1180: 1177: 1174: 1169: 1165: 1118: 1101:ball of radius 1086: 1044: 1041: 987: 981: 978: 975: 972: 968: 961: 957: 953: 950: 947: 944: 940: 932: 927: 923: 920: 916: 910: 906: 903: 899: 895: 889: 884: 881: 878: 875: 871: 864: 861: 857: 853: 850: 847: 844: 840: 832: 828: 822: 819: 816: 812: 805: 802: 800: 798: 795: 792: 787: 784: 781: 778: 774: 770: 769: 766: 760: 757: 753: 746: 743: 737: 733: 727: 724: 722: 720: 717: 714: 709: 706: 702: 698: 697: 678:gamma function 674:Leonhard Euler 657: 652: 648: 640: 636: 633: 628: 625: 619: 615: 608: 605: 600: 594: 591: 588: 585: 580: 576: 544:Main article: 541: 538: 443: 440: 425: 421: 417: 414: 392: 388: 384: 381: 361: 339: 335: 312: 308: 287: 255:, a ball is a 193:in general. A 170:. It may be a 144: 143: 58: 56: 49: 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 3461: 3450: 3447: 3445: 3442: 3440: 3437: 3435: 3432: 3431: 3429: 3418: 3414: 3410: 3406: 3402: 3398: 3397: 3391: 3387: 3383: 3379: 3375: 3371: 3367: 3362: 3357: 3353: 3349: 3348: 3342: 3338: 3334: 3330: 3326: 3322: 3318: 3317: 3311: 3310: 3303: 3300: 3294: 3291: 3286: 3284:9780262590204 3280: 3276: 3272: 3271: 3263: 3260: 3253: 3243: 3238: 3235: 3233: 3228:Volume of an 3226: 3224: 3221: 3219: 3216: 3213: 3207: 3205: 3202: 3199: 3196: 3194: 3191: 3188: 3185: 3183: 3180: 3177: 3174: 3173: 3168: 3163: 3162: 3158: 3155: 3154: 3150: 3147: 3146: 3142: 3139: 3138: 3134: 3131: 3130: 3126: 3125: 3124: 3120: 3112: 3110: 3104: 3103:diffeomorphic 3100: 3091: 3085: 3080: 3066: 3062: 3048: 3037: 3031: 3022: 3012: 3010: 3006: 2994: 2982: 2979:-dimensional 2971: 2963: 2961: 2958: 2948: 2943: 2938: 2929: 2925: 2921: 2917: 2909: 2907: 2890: 2885: 2881: 2877: 2873: 2870: 2867: 2863: 2858: 2854: 2850: 2840: 2827: 2801: 2798: 2789: 2785: 2780: 2774: 2762: 2754: 2749: 2741: 2734: 2728: 2726: 2714: 2709: 2705: 2697: 2692: 2688: 2684: 2683: 2674: 2655: 2638: 2621: 2617: 2613: 2610: 2605: 2601: 2597: 2592: 2586: 2574: 2570: 2561: 2558: 2555: 2550: 2538: 2534: 2525: 2520: 2508: 2504: 2494: 2489: 2484: 2476: 2468: 2462: 2452: 2449: 2445: 2441: 2435: 2429: 2409: 2389: 2384: 2380: 2376: 2371: 2365: 2353: 2349: 2340: 2337: 2334: 2329: 2317: 2313: 2304: 2299: 2287: 2283: 2273: 2268: 2263: 2255: 2230: 2227: 2224: 2210: 2202: 2198: 2187: 2185: 2182: 2169: 2163: 2157: 2137: 2134: 2131: 2111: 2105: 2097: 2093: 2085: 2069: 2049: 2029: 2009: 1989: 1966: 1958: 1954: 1933: 1927: 1924: 1921: 1915: 1909: 1906: 1903: 1897: 1874: 1860: 1852: 1850: 1837: 1834: 1831: 1828: 1808: 1805: 1799: 1791: 1787: 1763: 1757: 1745: 1737: 1733: 1721: 1705: 1685: 1679: 1671: 1667: 1663: 1651: 1643: 1639: 1625: 1611: 1605: 1597: 1593: 1589: 1577: 1569: 1565: 1558: 1552: 1544: 1540: 1516: 1508: 1504: 1495: 1470: 1462: 1458: 1445: 1439: 1435: 1431: 1427: 1423: 1418: 1416: 1412: 1407: 1405: 1401: 1397: 1393: 1389: 1385: 1381: 1377: 1372: 1370: 1369: 1362: 1352: 1339: 1333: 1330: 1324: 1321: 1318: 1312: 1309: 1306: 1303: 1300: 1294: 1288: 1280: 1276: 1258: 1252: 1244: 1239: 1226: 1220: 1217: 1211: 1208: 1205: 1199: 1196: 1193: 1190: 1187: 1181: 1175: 1167: 1163: 1140: 1136: 1132: 1125: 1121: 1102: 1084: 1070: 1062: 1056: 1052: 1042: 1040: 1036: 1032: 1028: 1020: 1012: 1007: 1002: 985: 979: 976: 973: 970: 966: 959: 955: 951: 948: 945: 942: 938: 930: 925: 921: 918: 914: 908: 904: 901: 897: 893: 887: 882: 879: 876: 873: 869: 862: 859: 855: 851: 848: 845: 842: 838: 830: 826: 820: 817: 814: 810: 803: 801: 793: 785: 782: 779: 776: 772: 764: 758: 755: 751: 744: 741: 735: 731: 725: 723: 715: 707: 704: 700: 687: 683: 679: 675: 655: 650: 646: 638: 634: 631: 626: 623: 617: 606: 603: 598: 592: 586: 578: 574: 564: 558: 547: 539: 537: 533: 528: 522: 517: 514:bounded by a 513: 512: 505: 500: 496: 489:In Euclidean 487: 446:In Euclidean 441: 439: 423: 419: 415: 412: 390: 386: 382: 379: 359: 337: 333: 310: 306: 285: 277: 273: 269: 265: 260: 258: 254: 250: 247:bounded by a 246: 242: 238: 234: 230: 226: 222: 215: 211: 204: 196: 192: 191:metric spaces 188: 183: 181: 177: 173: 169: 165: 164: 160:bounded by a 159: 155: 151: 140: 137: 129: 118: 115: 111: 108: 104: 101: 97: 94: 90: 87: –  86: 82: 81:Find sources: 75: 71: 65: 64: 59:This article 57: 53: 48: 47: 41: 37: 32: 19: 3400: 3394: 3351: 3345: 3320: 3314: 3298: 3293: 3269: 3262: 3241: 3159: 3151: 3143: 3135: 3127: 3122: 3092: 3078: 3064: 3060: 3049: 3035: 3032:(hypercube) 3020: 3013: 2993:homeomorphic 2980: 2967: 2956: 2946: 2936: 2913: 2790: 2783: 2772: 2760: 2752: 2747: 2739: 2732: 2729: 2712: 2707: 2695: 2690: 2686: 2680: 2672: 2636: 2200: 2194: 2183: 2083: 2082:) copy of a 1856: 1446: 1437: 1422:metric space 1419: 1408: 1373: 1366: 1360: 1353: 1256: 1247: 1242: 1240: 1138: 1134: 1130: 1123: 1116: 1100: 1061:metric space 1054: 1050: 1046: 1034: 1030: 1026: 1018: 1010: 1003: 562: 556: 549: 531: 520: 509: 503: 488: 445: 271: 267: 261: 257:line segment 220: 213: 206: 202: 194: 184: 179: 171: 168:solid sphere 167: 161: 158:solid figure 153: 147: 132: 123: 113: 106: 99: 92: 80: 68:Please help 63:verification 60: 39: 3187:Formal ball 2725:Lamé curves 2243:and defines 1492:denote the 1440:the metric 668:where  495:hypersphere 470:. A closed 458:and center 278:the closed 214:hypersphere 172:closed ball 150:mathematics 18:Closed ball 3428:Categories 3254:References 3237:Octahedron 3117:See also: 1982:of points 1864:with norm 1722:, one has 1378:under the 1264:away from 1151:away from 1075:, and let 482:away from 126:March 2024 96:newspapers 3417:119483499 3386:119438515 3275:MIT Press 3034:(0, 1) ⊆ 2991:which is 2871:… 2836:∞ 2832:‖ 2825:‖ 2805:∞ 2704:Chebyshev 2691:diagonals 2687:Manhattan 2559:⋯ 2453:∈ 2338:⋯ 2228:≥ 2204:with the 2084:unit ball 1931:‖ 1925:− 1919:‖ 1878:‖ 1875:⋅ 1872:‖ 1832:∈ 1753:¯ 1718:with the 1659:¯ 1590:⊆ 1585:¯ 1559:⊆ 1478:¯ 1384:hypercube 1368:unit ball 1331:≤ 1310:∣ 1304:∈ 1197:∣ 1191:∈ 1033:− 1) ⋅ (2 922:π 827:π 732:π 682:factorial 614:Γ 599:π 416:⁡ 383:⁡ 203:hyperball 180:open ball 3449:Topology 3223:Manifold 3204:3-sphere 3169:See also 3086:of  3047:-cube . 2480:‖ 2474:‖ 2259:‖ 2253:‖ 1821:for any 1430:topology 499:interval 276:topology 225:)-sphere 3444:Spheres 3366:Bibcode 3337:2690391 3248:metric. 3212:-sphere 3145:segment 3113:Regions 3109:-ball. 2930:subset 2920:bounded 2682:taxicab 1494:closure 1411:bounded 1396:compact 1097:⁠ 1077:⁠ 1067:with a 508:, is a 251:. In a 156:is the 110:scholar 3415:  3384:  3335:  3281:  3198:Sphere 3137:sector 3099:smooth 3072:-ball 2928:convex 2926:, and 2775:> 2 2750:, the 2737:, the 1624:it is 1434:unions 1404:convex 1363:> 0 1243:closed 1069:metric 1013:+ 1)!! 540:Volume 527:sphere 516:circle 268:sphere 245:volume 237:circle 163:sphere 112:  105:  98:  91:  83:  3434:Balls 3413:S2CID 3382:S2CID 3356:arXiv 3333:JSTOR 3232:-ball 3161:wedge 3153:shell 3030:-cube 3026:unit 2770:with 2761:edges 2708:sides 2209:-norm 2195:In a 2191:-norm 1390:is a 1382:is a 1059:be a 529:when 518:when 501:when 466:from 239:. In 210:-ball 117:JSTOR 103:books 3279:ISBN 3176:Ball 3076:and 2942:norm 2924:open 2777:are 2730:For 2634:For 2611:< 1857:Any 1779:but 1447:Let 1426:base 1365:. A 1241:The 1218:< 1047:Let 1037:+ 1) 550:The 511:disk 272:ball 233:disk 195:ball 154:ball 152:, a 89:news 40:ball 38:, a 3405:doi 3374:doi 3325:doi 3129:cap 3050:An 2983:of 2944:on 2934:of 2844:max 2786:= 2 2735:= 3 2685:or 2639:= 2 1626:not 1254:or 1128:or 1110:in 1023:as 1021:+ 1 676:'s 672:is 560:in 534:= 3 523:= 2 506:= 1 413:int 405:or 380:int 325:or 216:or 205:or 197:in 148:In 72:by 34:In 3430:: 3411:. 3401:42 3399:. 3380:. 3372:. 3364:. 3352:13 3350:. 3331:. 3321:62 3319:. 3301:. 3277:. 3273:. 3090:. 3063:= 3011:. 2960:. 2922:, 2918:, 2781:. 1444:. 1268:, 1155:, 1137:; 1053:, 1039:. 1025:(2 1009:(2 536:. 486:. 438:. 259:. 223:−1 3419:. 3407:: 3388:. 3376:: 3368:: 3358:: 3339:. 3327:: 3287:. 3245:1 3242:l 3230:n 3210:n 3107:n 3095:n 3088:B 3079:R 3074:B 3070:n 3065:m 3061:n 3056:m 3052:n 3045:n 3041:n 3036:R 3028:n 3021:R 3016:n 3001:n 2997:n 2989:X 2985:X 2977:n 2973:X 2957:R 2952:X 2947:R 2937:R 2932:X 2895:} 2891:| 2886:n 2882:x 2878:| 2874:, 2868:, 2864:| 2859:1 2855:x 2851:| 2847:{ 2841:= 2828:x 2802:= 2799:p 2784:p 2773:p 2767:p 2765:L 2756:∞ 2753:L 2743:1 2740:L 2733:n 2721:p 2716:2 2713:L 2699:∞ 2696:L 2676:1 2673:L 2656:2 2651:R 2637:n 2622:. 2618:} 2614:r 2606:p 2602:/ 2598:1 2593:) 2587:p 2582:| 2575:n 2571:x 2566:| 2562:+ 2556:+ 2551:p 2546:| 2539:2 2535:x 2530:| 2526:+ 2521:p 2516:| 2509:1 2505:x 2500:| 2495:( 2490:= 2485:p 2477:x 2469:: 2463:n 2458:R 2450:x 2446:{ 2442:= 2439:) 2436:r 2433:( 2430:B 2410:r 2390:, 2385:p 2381:/ 2377:1 2372:) 2366:p 2361:| 2354:n 2350:x 2345:| 2341:+ 2335:+ 2330:p 2325:| 2318:2 2314:x 2309:| 2305:+ 2300:p 2295:| 2288:1 2284:x 2279:| 2274:( 2269:= 2264:p 2256:x 2231:1 2225:p 2214:p 2212:L 2207:p 2201:R 2189:p 2170:. 2167:) 2164:r 2161:( 2158:B 2138:0 2135:= 2132:y 2112:. 2109:) 2106:0 2103:( 2098:1 2094:B 2070:y 2050:r 2030:r 2010:y 1990:x 1970:) 1967:y 1964:( 1959:r 1955:B 1934:. 1928:y 1922:x 1916:= 1913:) 1910:y 1907:, 1904:x 1901:( 1898:d 1862:V 1838:. 1835:X 1829:p 1809:X 1806:= 1803:] 1800:p 1797:[ 1792:1 1788:B 1767:} 1764:p 1761:{ 1758:= 1749:) 1746:p 1743:( 1738:1 1734:B 1706:X 1686:. 1683:] 1680:p 1677:[ 1672:r 1668:B 1664:= 1655:) 1652:p 1649:( 1644:r 1640:B 1612:, 1609:] 1606:p 1603:[ 1598:r 1594:B 1581:) 1578:p 1575:( 1570:r 1566:B 1556:) 1553:p 1550:( 1545:r 1541:B 1520:) 1517:p 1514:( 1509:r 1505:B 1474:) 1471:p 1468:( 1463:r 1459:B 1442:d 1361:r 1356:p 1340:. 1337:} 1334:r 1328:) 1325:p 1322:, 1319:x 1316:( 1313:d 1307:M 1301:x 1298:{ 1295:= 1292:] 1289:p 1286:[ 1281:r 1277:B 1266:p 1262:r 1257:B 1250:r 1248:B 1227:. 1224:} 1221:r 1215:) 1212:p 1209:, 1206:x 1203:( 1200:d 1194:M 1188:x 1185:{ 1182:= 1179:) 1176:p 1173:( 1168:r 1164:B 1153:p 1149:r 1145:M 1141:) 1139:r 1135:p 1133:( 1131:B 1126:) 1124:p 1122:( 1119:r 1117:B 1112:M 1108:p 1104:r 1085:r 1073:d 1065:M 1057:) 1055:d 1051:M 1049:( 1035:k 1031:k 1027:k 1019:k 1017:2 1011:k 986:. 980:1 977:+ 974:k 971:2 967:r 960:! 956:) 952:1 949:+ 946:k 943:2 939:( 931:k 926:) 919:4 915:( 909:) 905:! 902:k 898:( 894:2 888:= 883:1 880:+ 877:k 874:2 870:r 863:! 860:! 856:) 852:1 849:+ 846:k 843:2 839:( 831:k 821:1 818:+ 815:k 811:2 804:= 797:) 794:r 791:( 786:1 783:+ 780:k 777:2 773:V 765:, 759:k 756:2 752:r 745:! 742:k 736:k 726:= 719:) 716:r 713:( 708:k 705:2 701:V 670:Γ 656:, 651:n 647:r 639:) 635:1 632:+ 627:2 624:n 618:( 607:2 604:n 593:= 590:) 587:r 584:( 579:n 575:V 563:n 557:r 552:n 532:n 521:n 504:n 491:n 484:x 480:r 476:r 472:n 468:x 464:r 460:x 456:r 452:n 448:n 424:n 420:D 391:n 387:B 360:n 338:n 334:D 311:n 307:B 286:n 221:n 218:( 208:n 199:n 139:) 133:( 128:) 124:( 114:· 107:· 100:· 93:· 66:. 20:)

Index

Closed ball

Euclidean space

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