已知x+y=1/2,则1/2x^2+xy+1/2y^2的值为()
问题描述:
已知x+y=1/2,则1/2x^2+xy+1/2y^2的值为()
答
填1/8
1/2x^2+xy+1/2y^2
=1/2(x^2+2xy+y^2)
=1/2(x+y)^2
=1/2*1/4
=1/8