Recent content by kevinlightman

  1. K

    Determining the type of critical point when the second derivative test fails

    Homework Statement For example with f(x,y) = x2y + xy2 Homework Equations The Attempt at a Solution Well I know there is a critical point at (0,0). So I calculated the second derivatives but they are all 0 here so that doesn't help. I also tried using the Taylor expansion to...
  2. K

    Proving Continuity for Composition of Functions: f(x,y)=g(x)

    Homework Statement Prove that if g:R->R is continuous at a then f(x,y)=g(x) is continuous at (a,b) \forall b \in R Homework Equations The Attempt at a Solution So we know \foralle>0 \existsd>0 s.t. \forallx\inR where |x-a|<d we have |g(x) - g(a)|<e So I've said as \forallb\inR...