• 2022-06-01
    求幂级数的收敛半径与收敛区域.[tex=4.0x1.5]Xdav2khU6mDVwWx3MkeDDjPfsDmz2505cx6KRPCh8Jk=[/tex],[tex=4.786x1.286]qY2WXCNTTtm52rrZdeYoxQ==[/tex].
  • 解: 由于[tex=6.357x2.143]I5PocycXYSmqX9keDWPEO3D+UX8eE8/zgBb1EQOUoWflWvrMVhPHtIcec0I+uJyoNxtmpVDYQ1mTjmiZLjbP4Q==[/tex] , 所以收敛半径为[tex=3.786x1.286]DFLjy6u2JPuCSoOdV3R1ow==[/tex], 收敛域为[tex=4.643x1.286]kWKrbE2Y4JZYxfdbsdRqUvt8T2qNtBnhIme8hhtrgR8=[/tex].

    举一反三

    内容

    • 0

      【1】求级数X^n/n^3的收敛域【2】求级数(2^n/n+1)*x^n的收敛半径

    • 1

      设幂级数[tex=3.643x3.286]WGu493lWbQkNjIXIJ06onV6IZmMDrYShNGcPME8shwWKH5T1GYVkFqbYkQtvxgXS[/tex]的收敛半径为[tex=1.143x1.214]WB5oUFU97imVoOqmwwnMtg==[/tex], 而[tex=3.5x3.429]UU1qstNjdmzg7TFKGbeGXsJXpXGu4k7SZ5Pl374mxwk=[/tex]的收敛半径为[tex=1.143x1.214]akFdfHl3PdcRxRUQleHWdA==[/tex].若把幂级数[tex=6.214x3.286]WGu493lWbQkNjIXIJ06oneLZcJFoQ3BGITMlybWara2JPRKknBTl8nFXbTZweoPu0vBt34L3pxIcH/n/A76GVQ==[/tex]的收敛半径记为[tex=0.786x1.0]AOSTmhvIsOwsdZlGoks7dg==[/tex], 证明:当 [tex=3.571x1.214]UwYj7//Vchh6BHOGv2BcaKcde3PLpSYYPS7ulmfNRD8=[/tex]时, [tex=7.071x1.357]KREFzHfNLktQlPN7y/7IF7Vgs1XtsMgQQ7IJi/yWGRM9VyMyXJwThLHQUItzCk3I[/tex].

    • 2

      若已知级数[tex=3.714x3.286]WGu493lWbQkNjIXIJ06onT3QU0jn8OIdvbSEozq++L5iYU5MhSc0wTrCNvECtMFc[/tex] 的收敛半径为[tex=6.5x1.357]8WZN0goBGCBxHj8z0du2FBgWhVfUgmq9Pzh/8Sw4nTY=[/tex]. 试证级数 [tex=6.929x3.286]WGu493lWbQkNjIXIJ06onUhrA629m7A11jL1rVa4kmWH21E8JlR8KYWhCJznEEw9U3RA/R441vaWNWIygkauUA==[/tex]的收敛半径为[tex=7.571x2.786]xGuXb+WGabExcMy4WVzhLN8mjKojv7R2UqsYJrKBKwui3V8ncv9qmx8RA1F5HJcu7Tv34ISICAeBYbC2/o7srg==[/tex]

    • 3

      确定下列级数的收敛半径与收敛域:[tex=4.0x3.071]wI03c1jobBnuEHvblGcXj3kuT91IDrR4LIhJ/lSGd9+hPcYE0b2w/iprlBB5l3dH[/tex]

    • 4

      设级数[tex=3.571x2.714]LCs/jzl+nr3KBTJXBn4IiTaMdvoS/p/hGL/Jv9ntegzmzbVBv3v1HeKEgBlLcyLM[/tex]的收敛半径为[tex=7.286x1.357]sTdvH6zX0iZNqILTrUec+Q==[/tex],证明:级数[tex=7.143x2.714]LCs/jzl+nr3KBTJXBn4IiVrR/a63aRDgwm6Ulx0DCkqQZXUGezi8qQqRicSofTkUWyb3f6mqFTz2twehW0bB7Q==[/tex]的收敛半径为[tex=7.714x2.786]88n1NtKriG0YM72QT5w50ARKMC3GTCC7OGxgHAYlBdhewQuMEfErAwKQ9wpi7IxVHJewFuEn04JodLhBCFDNBA==[/tex].