I have an assignment I will hand in for grading.
First part
I want to see if I have understood the consept correctly.
Determine max and min of $f(x,y)=xy $ on the triangle T with the corners $(0, 0), (0, 1)\:and\:(1, 0)$
I derived and got a critical point at $(0,0)$ which I evaluated to $0$.
Secondly I inspected the boundary lines of which only the hypotenuse was interesting x+y=1 where I only found one critical point and that was larger than 0.
Is it correct minimum value was 0?
Second part
Are there any analytical online tools where I can write functions and boundaries and get the max and min values?