lim(x趋向于π/4) sinx-cosx/tan^2 x-1
问题描述:
lim(x趋向于π/4) sinx-cosx/tan^2 x-1
答
lim(x-->π/4)( sinx-cosx)/(tan² x-1)=lim(x-->π/4)( sinx-cosx)/(sin² x/cos²x-1)=lim(x-->π/4)( sinx-cosx)cos²x/(sin² x- cos²x)=lim(x-->π/4)( sinx-cosx)cos²x/(si...