Additional Mathematics 0606 / Trigonometry / 1.211.21: Cosine graph: amplitude, period and sketch0606/12/O/N/20 — Question 3 · 5 marksMark as done · Save for later · Show all solutions(a)Write down the amplitude of 2cosx3−12\cos\tfrac{x}{3} - 12cos3x−1.[1]▸ Answer(b)Write down the period of 2cosx3−12\cos\tfrac{x}{3} - 12cos3x−1.[1]▸ Answer(c)On the axes below, sketch the graph of y=2cosx3−1y = 2\cos\tfrac{x}{3} - 1y=2cos3x−1 for −π≤x≤3π-\pi \le x \le 3\pi−π≤x≤3π radians.[3]▸ Answer▸ Official mark scheme← 1.9: Cosec identity and compound-angle equation1.33: Cosine–tangent to quadratic in sine →
