函数f(x)=4cos^2x+2sinxcosx+2sin^2x的最大值

问题描述:

函数f(x)=4cos^2x+2sinxcosx+2sin^2x的最大值

f(x)=4cos^2x+2sinxcosx+2sin^2x
=2+2cos^2x+sin2x
=sin2x+cos2x+3
=√2sin(2x+π/4)+3
故函数最大值是√2+3