Can hardly be. One equation relating two variables is a continuous curve in general. The present curve must be symmetrical about the 'diagonal' line x = y and go through that point. The curve might have more than one branch but if so no other branch cuts that line. Don't know what else they want you to say about it.
You might therefore try rotating the thing counter clockwise by 45° , then it is symmetrical around the new X axis f(X) = f(-X) and see if that inspires anything.