=设函数f(x)=-(cosx)^2-4tsin(x/2)*cos(x/2)+4t^3+t^2-3t+4,x∈R,其中|t|

问题描述:

=设函数f(x)=-(cosx)^2-4tsin(x/2)*cos(x/2)+4t^3+t^2-3t+4,x∈R,其中|t|

f(x)=(sinx-t)2+4t3-3t=3
g(t)=4t3-3t+3
g'(x)=12t2-4=4*(3t2-1)
(-1,-3分之根号3)和(3分之根号3,1)递增 (-三分之根号三,三分之根号三)递减