Hello, i'm looking for an explanation of a rule I used to solve a problem. I came to the correct answer in the end, but I do not understand why my first attempt went wrong. 1. The problem statement, all variables and given/known data Find the general solution to cot4θ = tan5θ 2. Relevant equations tanA = tanB => A = nπ + B tanα = a/b = cotβ Where α and β are complementary angles. 3. The attempt at a solution cot4θ = tan5θ tan(π/2 - 4θ) = tan5θ π/2 - 4θ = nπ + 5θ 9θ = π/2 - nπ θ = π/18 (2n - 1) The above is not given as a solution in my book and the following is said to be correct. 5θ = nπ + π/2 - 4θ 9θ = nπ + π/2 θ = π/18 (2n + 1) Why is this? Thanks!