![求 lim(x→∞)[sin(2/x)+cos(1/x)]^x的极限。需要详细步骤。谢谢!](/img/78450052.jpg)
lim(x→∞)[sin(2/x)+cos(1/x)]^x的极限。需要详细步骤。谢谢!
解答:
lim(x→∞)[sin(2/x)+cos(1/皮郑x)]^x
=lim(x→∞)[1+(sin(2/x)+cos(1/x)-1)]^x
=lim(x→∞)[1+(sin(2/x)+cos(1/x)-1)]^[1/((sin(2/x)+cos(1/x)-1))]*[x*(燃晌颂(sin(2/x)+cos(1/谨悉x)-1))]
=e^lim[x*((sin(2/x)+cos(1/x)-1))]
=e^lim(t→0)[((sin(2t)+cos(t)-1))/t]
=e^lim(t→0)[2(sin(2t)/2t+(cos(t)-1)/t)]
=e^(2-0)=e^2