Question

求证：无论x、y为何值,4x^2-8x 9y^2 18y 35的值恒为正.

Answer 1

4x^2-8x 9y^2 18y 35

=4(x-1)^2+9(y+1)^2+22

>=22

无论x、y为何值,4x^2-8x 9y^2 18y 35的值恒为正.