已知a+b=2,ab=2,求1/2^3b+a^2b^2+1/2ab^3的值
问题描述:
已知a+b=2,ab=2,求1/2^3b+a^2b^2+1/2ab^3的值
答
(1/2)a^3b+a^2b^2+(1/2)ab^3
=(1/2)ab(a^2+2ab+b^2)
=(1/2)ab(a+b)^2
=(1/2)*2*2^2
=4