1. The problem statement, all variables and given/known data At x=3 does the function y=x^3 + (x-3)^(1/3) have a vertical tangent, cusp, corner or none? 3. The attempt at a solution I took the derivative y'=3x^2 + 1 / 3x^(2/3) then i replaced 3 in which gave 27 + 1 / 0 I don't understand how to come to the correct conclusion following this step. Vertical tangent comes to mind since 1 / 0 is a vertical line, but I don't know how to prove it using limits.