Question

函数y=cos^2x+sinxcosx的最大值 要过程

Answer 1

y= (cosx)² + sinxcosx = 1/2 - (cos2x)/2 + (sin2x)/2 = 1/2 + (根号2)/2(sin(2x+π/4))
最大值 = 1/2 + （根号2）/2

Answer 2

cos^2x=（cos2x+1）/2
sinxcosx=sin2x/2
所以f(x)=（cos2x+sin2x+1）/2=(2^(1/2)sin(x+45°)+1)/2
所以最大值为(2^(1/2)+1)/2