Question about plotting indifference curves

Question

So I am doing a last year paper on microeconomics and I'm asked to find pareto efficiencies, cores and so on within the edgeworth box. So what I want to know is that when they give me in this exercise the consumer 1 utility as $xy$, how do I plot this $xy$ within the edgeworth box? I want to know its shape, and the same goes for all cobbdouglas functions… the only additional information given that I think is useful is total endowment and initial endowment.

Answer 1

$$U(x,y)=x\cdot y\Rightarrow U(x,y)=c\Rightarrow x\cdot y(x)=c\Rightarrow y(x)=\dfrac{c}{x}$$