求y=sin(x/2),y=(sinx)^2和y=[sin(x/2)]^2三个函数的导数?

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求y=sin(x/2),y=(sinx)^2和y=[sin(x/2)]^2三个函数的导数?

sin'(x/2)=cos(x/2)(x/2)'=cos(x/2)/2
[(sinx)^2]'=2sinx(sinx)'=2sinxcosx=sin(2x)
[sin(x/2)]^2 '=2sin(x/2)[sin(x/2)]'=2sin(x/2)cos(x/2)(x/2)'=sinx/2

[sin(x/2)]’=cos(x/2)
(sin²x)'=(sinx)'sinx+sinx(sinx)'
=sin(2x)
[sin²(x/2)]'=sin(x/2)'sin(x/2)+sin(x/2)sin(x/2)'
=cos(x/2)sin(x/2)+sin(x/2)cos(x/2)
=sinx

[sin(x/2)]’=cos(x/2)
(sin²x)'=(sinx)'sinx+sinx(sinx)'
=sin(2x)
[sin²(x/2)]'=sin(x/2)'sin(x/2)+sin(x/2)sin(x/2)'
=cos(x/2)sin(x/2)+sin(x/2)cos(x/2)
=sinx