2x³-x²+m
=2x³+x²-2x²-x+x +1/2 +m-1/2
=x²(2x+1)-x(2x+1)+(1/2)(2x+1)+(m-1/2)
=(2x+1)(x²-x +1/2)+(m-1/2)
多项式能有因式2x+1,能被2x+1整除,因此常数项m-1/2=0
m=1/2
2x³-x²+m
=2x³+x²-2x²-x+x +1/2 +m-1/2
=x²(2x+1)-x(2x+1)+(1/2)(2x+1)+(m-1/2)
=(2x+1)(x²-x +1/2)+(m-1/2)
多项式能有因式2x+1,能被2x+1整除,因此常数项m-1/2=0
m=1/2