三角函数带根号化简
问题描述:
三角函数带根号化简
根号下1-sinx 根号下1+cos 这两个式子分别怎么化简?
答
√(1-sinx)=√[(sin^2(x/2)-2sin(x/2)cos(x/2)+cos^2(x/2)].∴√(1-sinx)=√[(sin(x/2)-cos(x/2)]^2=|six(x/2)-cos(x/2)|.当0≤x/2≤π/4时,即0≤x≤π/2,sin(x/2)≤cos(x/2),∴原式=|sin(x/2)-cos(x/2)|=-[sin(x/2)...