I have a function given below:
$f(x,y) = \log_2(1 - xe^y + c + ax + axe^y)$
I was hoping to find $(x,y)$ that minimizes this function. The constraints are $0 < x <1$ and $y > 0$. Here, both $x$ and $y$ are discrete. I wasn't sure if the function is convex or not. So, I tried checking and I think the function is $quasiconcave$. How can I find $(x,y)$ in this case such that it minimizes $f$?