My Calculus Course: https://www.youtube.com/c/MrHelpfulNotHurtful/playlists?view=50&sort=dd&shelf_id=1
I will show you how to find the equation of a line tangent to a trig function at the point (π, -1).
Also, I will show you how to find all the x-values where the function will have a horizontal tangent line on the interval (0, 2π).