已知 f(sinx/2)=cosx+1,则f(cosx/2)等于多少
网友回答
f(sinx/2)=cosx+1=2-2sin²x/2
所以f(x)=2-2x²
f(cosx/2)=2(1-cos²x/2)=2sin²x/2
======以下答案可供参考======
供参考答案1:
f(sinx/2)=cosx+1
= 1- 2(sinx/2)^2 +1
= 2- 2(sinx/2)^2
f(cosx/2) = 2- 2(cosx/2)^2
供参考答案2:
∵f(sinx/2)=cosx+1
∴f(cosx/2)=f[sin(π/2-x/2)]=cos(π-x)+1=1-cosx