Further Pure Mathematics 4PM1 / Trigonometry / 1.81.8: Solve three trigonometric equations4PM1/2R/June/2022 — Question 7 · 12 marksMark as done · Save for laterSolve(a) cos (3x−15)∘=32,0≤x<180,\mathrm{cos}\,(3x-15)^\circ=\frac{\sqrt{3}}{2}, \qquad 0\leq x<180,cos(3x−15)∘=23,0≤x<180,(4)(b) 3tan y∘+4sin y∘=0,−180≤y<180,3\mathrm{tan}\,y^\circ+4\mathrm{sin}\,y^\circ=0, \qquad -180\leq y<180,3tany∘+4siny∘=0,−180≤y<180,giving your answers to one decimal place where appropriate,(4)(c) cos θ∘=3sin2θ∘−1,−180≤θ<180,\mathrm{cos}\,\theta^\circ=3\mathrm{sin}^2\theta^\circ-1, \qquad -180\leq\theta<180,cosθ∘=3sin2θ∘−1,−180≤θ<180,giving your answers to one decimal place where appropriate.(4)▸ Mark scheme← 1.7: 4PM1/2R/June/2022 — Question 61.9: 4PM1/1/June/2021 — Question 2 →
