f(x)+2f(-x)=6x平方-3x+3 ---------------(1)
将x换成-x
f(-x)+2f(x)=6x²+3x+3 -------------------(2)
(1)-(2)*2
-3f(x)=6x²-3x+3-2(6x²+3x+3)
∴ -3f(x)=-6x²-9x-3
∴ f(x)=2x²+3x+1
f(x)+2f(-x)=6x平方-3x+3 ---------------(1)
将x换成-x
f(-x)+2f(x)=6x²+3x+3 -------------------(2)
(1)-(2)*2
-3f(x)=6x²-3x+3-2(6x²+3x+3)
∴ -3f(x)=-6x²-9x-3
∴ f(x)=2x²+3x+1