f(x)=x^4-2x^2

f(x)=x^2+x (x f(X)=f(X+2)(x 设f（x)满足f(-x)=-f(x),f(x)=f(4-x),x∈[0,2)时,f(x)=x,则f(11.5)等于? f(x+1)+f(x-1)=2x²-4x,求f（x）? f(x+1)+f(x-1)=4x^3-2x求f(x) f(x)=min{x^2-2,x,4-x} f(x)= 4-x^2 ,|f(x)|2求f(f(x)) 怎样由f(x+2)=1/f(x)得出f(x+4)=f(x) f(x+2)=-f(x)怎么得到f(x+4)=f(x)? 二次函数f(x)满足f(x+1)+f(x-1)=2x^2+4x,求f(x) 若函数f(x)满足f(x)+2f(1/x)=5x+4/x,则f(x)= f(x)=x|x|+2x (x 函数f(x)={(1/2)^x,(x>4),f(x+3),(x 函数f(x)={(1/2)^x,(x>4),f(x+3),(x 已知f(x)={2^x,(x≥4);f(x+1)(x 设函数f(x)={(1/2)^x(x≥4),f(x+3)(x 函数f(x)=2-x,(x>=0);f(x)=|x^2+4x+2|(x 已知f(x)=x^-2(x