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limx→0sinx^2/(sinx)^2

题目详情
limx→0 sinx^2/(sinx)^2
▼优质解答
答案和解析
lim(x→0) sinx^2=0
lim(x→0) (sinx)^2=0
lim(x→0) sinx^2/(sinx)^2=lim(x→0) (sinx^2)'/[(sinx)^2]'
=lim(x→0) (2xcosx^2)/(2sinxcosx)
=lim(x→0) 2xcosx^2/(sin2x)
=lim(x→0) cosx^2/(sin2x/2x)
lim(x→0) cosinx^2=1 limx→0 sin2x/(2x)=1
=1