1. The problem statement, all variables and given/known data find the derivative of the function f(x)=arcsec(4x) 2. Relevant equations I think this is a Relevant equations. d/dx[arcsecu]=u'/(|u|(√u2-1) 3. The attempt at a solution f'(x)=4/(|4|(√42-1) =1/√15 I keep getting wrong in my online homework why?