1. The problem statement, all variables and given/known data 1. Calculate lim x->0 (xtanx/cos(2x)-1) without using L'Hospitals rule. 2. Relevant equations I am told that lim x->0 (sinx/x)=1 3. The attempt at a solution If I substitute 0 in it gets 0/0. I have tried several trig identities without luck.