1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution 1. The problem statement, all variables and given/known data 2. Relevant equations u = 1+tant du = sec^2(t) dt dt = du / sec^2(t) 3. The attempt at a solution It seems like I should be using substitution in the equation, however the exponent is messing things up for me. I recall from derivatives how they interact with the chain rule, but am not sure how this would work backwards in integration. Something like, I(u^3)(sec^2(t)) = (u^4/4)((sec^2(t)) (tan(t)) Except I haven't gotten rid of the t variable and now have t and u. Any points are welcome.