1. The problem statement, all variables and given/known data The P(a,b) be a point on the curve √x + √y = 1. Show that the slope of the tangent P is -√b/a 2. Relevant equations ? 3. The attempt at a solution Apparently this is an implicit differentiation problem, however we haven't learned or discussed implicit differentiation at all. I ran it through wolfram alpha to help give an idea of what to do and got the answer I was supposed to, but looking at the process I don't understand it at all. It's here: http://www.wolframalpha.com/input/?i=the implicit derivative of sqrt x + sqrt y = 1 Is there any other way to solve this? If not, can anyone explain the first few steps, or link me to the solution of a similar problem? Thanks!