1.根据诱导公式cos(π/2-x)=sinx,则f(x)=sinx^2-asinx+1/2a.
2.f(x)变形为:f(x)=(sinx-1/2*a)^2-1/4*a+1/2a.
3.a为常数,-1/4*a+1/2a是一个固定的常数,要想使有最小值,则(sinx-1/2*a)^2=0,即sinx=1/2*a,x∈[-π/6,5π/6],-1/2=
1.根据诱导公式cos(π/2-x)=sinx,则f(x)=sinx^2-asinx+1/2a.
2.f(x)变形为:f(x)=(sinx-1/2*a)^2-1/4*a+1/2a.
3.a为常数,-1/4*a+1/2a是一个固定的常数,要想使有最小值,则(sinx-1/2*a)^2=0,即sinx=1/2*a,x∈[-π/6,5π/6],-1/2=