A=-1/2x 3x2-x3,B=2(x3 x2-1/2x-1),求1/2(A B)-1/3(A-B)的值
问题描述：
A=-1/2x 3x2-x3,B=2(x3 x2-1/2x-1),求1/2(A B)-1/3(A-B)的值
答
1/2(A+ B)-1/3(A-B)=1/2A+1/2B-1/3A+1/3B=1/6A+5/6B=1/6*(-1/2x+3x²-x³)+5/6*(2x³+2x²-x-2)=-1/12x+x²/2-x³/6+5/3x³+5x²/3-5/6x-5/3=3/2x³+13/6x²-11/12x-5/3不...