f(x)=sinx+sinxcosx=sinx+1/2sin2x
F(X)=-cosx-1/2cos2x=-cosx-1/2(2(cosx)^2-1)=-cosx-(cosx)^2+1/2
设t=-cosx
F(t)=-t^2+t+1/2 t在-1与1之间 t=1/2时F(t)最大为3/4
t=-1时最小-5/4
f(x)=sinx+sinxcosx=sinx+1/2sin2x
F(X)=-cosx-1/2cos2x=-cosx-1/2(2(cosx)^2-1)=-cosx-(cosx)^2+1/2
设t=-cosx
F(t)=-t^2+t+1/2 t在-1与1之间 t=1/2时F(t)最大为3/4
t=-1时最小-5/4