又f(x),g(x)均为实系数多项式，从而必有 g(x)= h(x)= 0.:: f(x) = g(x) = h(x) = 0.(2）在C上不成立．如取f(x) = 0, g()=ix, h(x) = x81.2一元多项式F§1.2 一元多项式 (2) 在 C上不成立．如取 f x g x ix h x x ( ) 0, ( ) , ( ) = = = 从而必有 g x h x ( ) ( ) 0. = =  = = = f x g x h x ( ) ( ) ( ) 0. 又 f x g x ( ), ( ) 均为实系数多项式