Show that, for small values of θ\thetaθ measured in radians,
3cos2θ+sin4θ−2tan3θ≈A+Bθ+Cθ2 3 \cos 2\theta + \sin 4\theta - 2 \tan 3\theta \approx A + B\theta + C\theta^2 3cos2θ+sin4θ−2tan3θ≈A+Bθ+Cθ2where AAA, BBB and CCC are constants to be found.
Use your answer to part (a) to find an approximation for
3cos0.12+sin0.24−2tan0.18 3 \cos 0.12 + \sin 0.24 - 2 \tan 0.18 3cos0.12+sin0.24−2tan0.18Give your answer to three decimal places.
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.