f(3x+1)=x^2-2x,f(4)=?

F(X)满足F(x)+2f(x分之1)=3X,求f(x) 已知f(x)满足2f(x)+f(1/x)=3x,求f(x) 已知f(x)满足2f(x)+f(1/x)=3x,求f(x)? 已知f(x)满足2f(x)+f(-x)=-3x+1,求f(x) f(x)=x(x-1)(x-2)(x-3)(x-4) f'(1)=? 函数f(x)={(1/2)^x,(x>4),f(x+3),(x 已知f(x+1)+2f(-x)=3x²+x,求f(x) f(x+2)>=f(x)+2,f(x+3) 二次函数f(x)满足f(x+1)+f(x-1)=2x^2+4x,求f(x) f(X)=f(X+2)(x 1.f(x)+2f(-x)=x的平方,求f（x) 2.已知f(x)满足f(x)+2f(1/x)=4x+3,求f(x) 设函数f(x)满足f(x)+2f(1/x)=x,求f(x)