Question #018ee

1 Answer
May 29, 2017

I would say C. III is true.

Explanation:

f(-x,-y) = (-x)^2+(-x)(-y)+(-y)^2 = x^2-x(-y)+y^2 = x^2+xy+y^2

Also, f(-x,y)=x^2-xy+y^2 and f(x,-y)=x^2-xy+y^2