(1)n=1æ¶
[e^(1/x)]'=e^(1/x)·(1/x)'
=-1/x^2·e^(1/x)
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[x^(k-1)·e^(1/x)]^{k}
=(-1)^k·e^(1/x)/x^(k+1)
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[x^(k)·e^(1/x)]^{k+1}
=[x·x^(k-1)·e^(1/x)]^{k+1}
=x·[x^(k-1)·e^(1/x)]^{k+1}
+(k+1)·x'·[x^(k-1)·e^(1/x)]^{k}
=x·[(-1)^k·e^(1/x)/x^(k+1)]'
+(k+1)·(-1)^k·e^(1/x)/x^(k+1)
=x·(-1)^k·[e^(1/x)·x^(-k-1)]'
+(k+1)·(-1)^k·e^(1/x)/x^(k+1)
=x·(-1)^k·e^(1/x)·(1/x)'·x^(-k-1)
+x·(-1)^k·e^(1/x)·[x^(-k-1)]'
+(k+1)·(-1)^k·e^(1/x)/x^(k+1)
=x·(-1)^k·e^(1/x)·(-1/x^2)·x^(-k-1)
+x·(-1)^k·e^(1/x)·(-k-1)·x^(-k-2)
+(k+1)·(-1)^k·e^(1/x)/x^(k+1)
=-(-1)^k·e^(1/x)·x^(-k-2)
+(-1)^k·e^(1/x)·(-k-1)·x^(-k-1)
+(k+1)·(-1)^k·e^(1/x)/x^(k+1)
=(-1)^(k+1)·e^(1/x)/x^(k+2)
-(-1)^k·e^(1/x)·(k+1)/x^(k+1)
+(k+1)·(-1)^k·e^(1/x)/x^(k+1)
=(-1)^(k+1)·e^(1/x)/x^(k+2)
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