1. The problem statement, all variables and given/known data Find the limit: lim (tanx-1)/(x-pi/4) x->pi/4 2. Relevant equations tanx = sinx/cosx 3. The attempt at a solution lim (sinx/cosx-1)/(x-pi/4) x->pi/4 lim [(sinx-cosx)/cosx]/(x-pi/4) x->pi/4 I have no idea what to do after this ): I also tried squaring the whole function and getting tan2x-1 = sec2x, but I get so lost on what to do with pi/4 because it just keeps becoming undefined! Thanks for your help!!