求极限lin→无穷3n/n^2+2n-1
[(2n+3n)/( 2n+1+3n+1)]\u7684\u6781\u9650,n\u8d8b\u4e8e\u65e0\u7a77\u4e0a\u4e0b\u9664\u4ee53^n
\u539f\u5f0f=lim[(2/3)^n+1]/[2*(2/3)^n+3]
(2/3)^n\u8d8b\u4e8e0
\u6240\u4ee5\u539f\u5f0f=(0+1)/(0+3)=1/3
n\u8d8b\u4e8e\u221e\u65f6\uff0c
[(-1)^n-n^2]/(2n^2+3n)
\uff1d\uff3b\uff0d1\uff0b\uff08\uff0d1\uff09\uff3en\uff0fn\uff3e2\uff3d\uff0f\uff082\uff0b3\uff0fn\uff09
n\u8d8b\u4e8e\u221e\u65f6\uff0cn\uff3e2\u8d8b\u4e8e\u221e\u6240\u4ee5\uff08\uff0d1\uff09\uff3en\uff0fn\uff3e2\u8d8b\u4e8e\u00b11\uff0f\u221e\uff1d0\uff0c3\uff0fn\u8d8b\u4e8e0
\u6240\u4ee5\u539f\u6781\u9650\uff1d\uff08\uff0d1\uff0b0\uff09\uff0f\uff082\uff0b0\uff09\uff1d\uff0d1\uff0f2
\u5e0c\u671b\u80fd\u591f\u5e2e\u52a9\u4f60\uff0c\u6709\u7591\u95ee\u6b22\u8fce\u8ffd\u95ee\uff0c\u52a9\u5b66\u4e60\u8fdb\u6b65\uff01
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