1)a-b=(-2cosx,2sinx/2-2cosx/2) f(x)=2+sinx-(1/4)[4cosx+4(sinx/2+cosx/2-2sinx/2cosx/2)] =2+sinx-cosx-(1-sinx) =2+sinx-(1-sinx)-1+sinx =sinx+2sinx 2)設(shè)g(x)上的點(diǎn)(x,y),則對(duì)應(yīng)f(x)的點(diǎn)為(-x,-y) ∴-y=sin(-x)+2sin(-x)=sinx-2sinx ∴y=-sinx+2sinx 即g(x)=-sinx+2sinx 3)h(x)=(-sinx+2sinx)-λ(sinx+2sinx)=(-1-λ)sinx+(2-2λ)sinx t=sinx在[-π/2,π/2]是單調(diào)增,∴h(x)在(-1-λ)t+(2-2λ)t在[-1,1]上單調(diào)增 h(x)是關(guān)于t的二次函數(shù),對(duì)稱軸為t=(2-2λ)/2(1+λ)=(1-λ)/(1+λ) 若-1-λ>0,λ