For a small angle θ\thetaθ, where θ \theta\,θ is measured in radians, show that
2cosθ+(sinθ+1)2≈2θ+32\cos\theta + (\sin\theta + 1)^2 \approx 2\theta + 32cosθ+(sinθ+1)2≈2θ+3
Hence determine an approximate solution of the equation
2cosθ+(sinθ+1)2=20tanθ2\cos\theta + (\sin\theta + 1)^2 = 20\tan\theta2cosθ+(sinθ+1)2=20tanθ
where θ \theta\,θ is small and positive.
225 exam-style questions on WJEC A Level Maths 3.5 Trigonometry (A-level only), covering 3.5.1 Trigonometry (A-level only), 3.5.2 Trigonometry (A-level only), 3.5.3 Trigonometry (A-level only), 3.5.4 Trigonometry (A-level only), 3.5.5 Trigonometry (A-level only), 3.5.6 Trigonometry (A-level only), 3.5.7 Trigonometry (A-level only), and 3.5.8 Trigonometry (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.