Additional Mathematics 0606 / Trigonometry / 3.203.20: Cosine: amplitude, period and sketch0606/22/M/J/21 — Question 5 · 5 marksMark as done · Save for later · Show all solutionsThe function fff is defined, for 0∘⩽x⩽810∘0^{\circ} \leqslant x \leqslant 810^{\circ}0∘⩽x⩽810∘, by f(x)=−cos2x3f(x) = -\mathrm{cos}\dfrac{2x}{3}f(x)=−cos32x.(a)Write down the amplitude of fff.[1]▸ Answer(b)Find the period of fff.[2]▸ Answer(c)On the axes, sketch the graph of y=f(x)y = f(x)y=f(x).[2]▸ Answer▸ Official mark scheme← 3.19: Polynomial factor and remainder3.21: Ln curve sketch and tangent →
