先化简:(2sinx-sin2x)/(sinx^2 tanx) =(2sinx-2sinxcosx)/sinx^2tanx =2(1-cosx)/sinx * sinx/cosx =2cosx(1-cosx)/sinx^2 =2cosx(1-cosx)/(1-cosx^2) =2cosx/1+cosx所以lim(x-0) (...
先化简:(2sinx-sin2x)/(sinx^2 tanx) =(2sinx-2sinxcosx)/sinx^2tanx =2(1-cosx)/sinx * sinx/cosx =2cosx(1-cosx)/sinx^2 =2cosx(1-cosx)/(1-cosx^2) =2cosx/1+cosx所以lim(x-0) (...