1. The problem statement, all variables and given/known data Suppose P(a,b) is a fixed point in Quadrant 1 of an xy-plane and line L is descending in the plane such that P is on line L. Let Q=(xknot,0) and R=(0,yknot) be the x and y intercepts for line L and let S= 1/(xknot + yknot) 1. Express S as a function of xknot 2. Find any extreme values for S I know how to do number 2 but number 1 stumps me, how do I get yknot to become xknot? 2. Relevant equations for 2. quotient rule 3. The attempt at a solution so far I have got L=-(y/x) + y using y=mx+b (descending line means it's linear right?) in another attempt I find the equation of the line using point RP and then PQ then setting them equal to each other to solve for yknot. I use that to plug into S. S would be expressed in terms of xknot and the a and b are constants. If I find the critical numbers of S with this, it comes out very ugly and does not seem like the answer. HOW DO I APPROACH THIS PROBLEM (it is supposedly an optimization problem).