Recent content by slash123

its finding the normal sorry, should of said that instead,, what I've put in as the question is all the questions asks.

Finding the Equation of Tangent line on cos wave! Find the equation of the normal line to y = 2cos ( 4x) at x = \pi / 3 I don't even know where to start with this question, i have searched the textbook and internet, help would be appreciated.