Question

What are the critical points of `f(x,y)=x^2+y^2-4x-6y+5`?

Answer 1

`(2, 3)`

Explanation:

`f_x = 2x - 4 qquad star`
`f_y = 2y - 6 qquad square`

critical points are at `f_x = f_y = 0`

from `star` and `square`, that is limited to point `(2, 3)`