数学问题
f(x)=(1-sinx)^0.5+(1+sinx)^0.5
=(sin^2(x/2)+cos^2(x/2)-2sin(x/2)cos(x/2))^0.5+(sin^2(x/2)+cos^2(x/2)+2sin(x/2)cos(x/2))^0.5
为什么?