1. The problem statement, all variables and given/known data I am trying to figure out how to solve for problems that give a function and ask for the critical points. However, the ones I am having difficulty with are the ones that have multiple trigonometric functions included in them. 2. Relevant equations Find the critical points of the following function on the given interval: f(x) = 8sin(x)+3cos(x) ; [-2∏, 2∏] 3. The attempt at a solution Once I find the derivative, I grouped the trigonometric functions onto one side to make: 8/3 = tan(x) However, I am at a loss as to how I can solve for x here? Our instructor never explained how we can solve for trigonometric functions without using the reference angles. I am trying to brush up on this stuff since I have calc II this fall, but am finding a couple things like this that we didn't cover. Please keep in mind when providing your solution and method to that solution that I have only taken calc I up to this point. Just throwing that out there in hopes that you take this into consideration and don't throw things out there that might go over my head at this point of my education. Thank you.