2x³-x²+m=2x³+x²-2x²-x+x+1/2+m-1/2=(2x+1)(x²-x+1/2)+(m-1/2)则必须m-1/2=0m=1/2
令f(x)=2x^3-x^2+m则根据余式定理,2x+1=2[x-(-1/2)]即f(-1/2)=0-0.25-0.25+m=0m=0.5
2x^3-x^2+m=(2x+1)x^2-2x^2+m=(2x+1)x^2-x(2x+1)+x+m=(2x+1)x^2-x(2x+1)+1/2(2x+2M)2M=1 M=1/2