Grade 12 calculus, derivatives of Trig, Exp & Log Functions. Answer full question please

Q1. Consider the function / (x) = - tan(x - #). a. Determine f '(x). [1 Mark] b. Determine the slope of the tangent to the curve f()() at the point with x-coordinate 4 . [1 Mark] c. Determine the equation of the tangent to the curve f()) at the point with x-coordinate 4 . 12 Marks]