1. The problem statement, all variables and given/known data ∫ sec2 (7-3θ) dθ 2. Relevant equations ∫ cos(kx+b)dx= ((sin(kx+b))/k)+C ∫ sin (kx+b)dx=-cos " (k and b are constants) 3. The attempt at a solution The answer in the book is: ∫ -1/3(tan(7-3x))+C. I assume by x they meant θ. The book only gave the two formulas above for solving this, but my question is can these by simplified and expanded by saying ∫ f(g(x)) dx = F(g(x))/g'(x)? Because I looked online for a rule like this and found nothing. If this involves U-substitution or something of the sort, I couldn't find that in the textbook. Also, if you have any really good textbooks or sources for learning integration I don't like my textbook.