大神帮我看看高等代数第14题怎么写?

2025-04-28 08:11:39
推荐回答(1个)
回答1:

lim(0-->π/9) ln[2cos(3x)]=ln[2cos(3*π/9)]=ln[2cos(π/3)]=ln(2*1/2)=ln1=0
lim(0-->)ln(sinx/x)=ln(x/x)=ln1=0
lim(x-->0)(1+3tan^2x)^(cot^2x)=lim(x-->0)(1+3tan^2x)^(1/tan^2x)
=lim(x-->0)(1+3tan^2x)^[3*1/(3tan^2x)]=lim(x-->0)[(1+3tan^2x)^(1/tan^2x)]^3=e^3