My Working:
So I have been practicing for my upcoming exam. This is from one of my past exam papers, and I am unable to solve it. The thing that confuses me is that the given pdf $f_X,_Y(x,k)$ involves $k$ and I am supposed to find value of $c$ in part $a$ which is not possible until $k$ is not known to me. Once I have $k$ it is pretty easy to find $c$ by integrating over the given domain equating it to $1$ and then solve for $c$. I have tried but calculations becomes messy and unreasonable that I feel stuck. Am I supposed to integrate given pdf w.r.t $dx$ $dk$ and $k$ is just assumed to be there? I don't know. Any help will be appreciated.
