f'(x)=4x^3-4x 所以可以设f(x)=x^4-2x^2+c又因为过定点(0,-5),所以f(0)=-5-5=0^4-2(0^2)+c → c=-5所以f(x)=x^4-2x^2-5令f'(x)＞0 → 4x^3-4x＞0 → 4x(x^2-1)＞0 → 4x(x-1)(x+1)＞0 → -1＜x＜0 或 x＞1所以f(x)的...