已知a+b=7/4,ab=3/4,求1/2a^2+1/2ab^2

问题描述:

已知a+b=7/4,ab=3/4,求1/2a^2+1/2ab^2

1/2a^2b+1/2ab^2
=1/2ab(a+b)
=1/2×3/4×7/4
=21/32