sin^2(x/2)]*[cos^2(x/2)]等于多少啊
问题描述：
sin^2(x/2)]*[cos^2(x/2)]等于多少啊
答
sin^2(x/2)]*[cos^2(x/2)]
=(sinx/2cosx/2)^2
=(1/2*2sinx/2cosx/2)^2
=sinx^2/4
答
[sin^2(x/2)]*[cos^2(x/2)]
=[sin(x/2)cos(x/2)]^2
=[(1/2)*2*sin(x/2)cos(x/2)]^2
=[(1/2)sinx]^2
=(1/4)(sinx)^2