推 pepaduck:謝謝 218.167.73.150 06/20 12:46
※ 引述《pepaduck (@@)》之銘言:
: 1.(c)
: 3 x
: lim ( 1 + sin -- )
: x->∞ x
: 想麻煩各位高手幫忙解答, 謝謝
= lim e^{xlog[1+sin(3/x)]}
x->∞
= e^lim{xlog[1+sin(3/x)]}
x->∞
令x=1/t
= e^lim {log[1+sin(3t)]}/(t)
t->0
0/0型
利用L'Hospital's Rule
= e^lim[3cos(3t)/(1+sin(3t)]
t->0
= e^3 #
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