AoPS Wiki talk:Problem of the Day/June 9, 2011
Let . Therefore, . Now, let be the inverse function of , so that . However, the in the LHS cancels out by the definition of an inverse function. Therefore, we have . Now we must find . Again by the definition of an inverse function, we have , and , so . Solving, we find that . Plugging this in to yields .
We know that is of the form , so we can start by plugging in which yields and plugging in gives , using the slope formula we can get