求证:cosx+sinx+1/cosx-sinx+1=1+sinx/cosx
问题描述:
求证:cosx+sinx+1/cosx-sinx+1=1+sinx/cosx
“/”前面为分子,后面为分母
答
左式上下同乘(cosx+sinx+1),则(cosx+sinx+1)^2左式=-------------------(cosx+1)^2-(sinx)^2(cosx)^2+(sinx)^2+1+2cosx+2sinx+2sinxcosx=-----------------------------------------(cosx)^2+1+2cosx-(sinx)^22[1+co...