Additional Mathematics 0606 / Trigonometry / 1.81.8: Amplitude, period and sketch of a cosine graph0606/11/O/N/20 — Question 2 · 5 marksMark as done · Save for later · Show all solutions(a)Write down the amplitude of 1+4cosx31 + 4\cos\tfrac{x}{3}1+4cos3x.[1]▸ Answer(b)Write down the period of 1+4cosx31 + 4\cos\tfrac{x}{3}1+4cos3x.[1]▸ Answer(c)On the axes below, sketch the graph of y=1+4cosx3y = 1 + 4\cos\tfrac{x}{3}y=1+4cos3x for −180°≤x≤180°-180^{\degree} \le x \le 180^{\degree}−180°≤x≤180°.[3]▸ Answer▸ Official mark scheme← 3.1: Trapezium with surds: perimeter, area, tan and sec1.9: Cosec identity and compound-angle equation →
