When x x\,x is small, show that sin(2x)cos(4x)\sin(2x) \cos(4x)sin(2x)cos(4x) can be approximated by 2x−16x32x - 16x^32x−16x3
Hence, approximate the value of sin(0.2)cos(0.4)\sin(0.2) \cos(0.4)sin(0.2)cos(0.4)
Calculate the percentage error in your approximation
317 exam-style questions on AQA A Level Maths 1.8 E: Trigonometry, covering 1.8.1 Trigonometric definitions, rules and radians, 1.8.2 Small angle approximations (A-level only), 1.8.3 Trigonometric functions and exact values, 1.8.4 Reciprocal and inverse trigonometric functions (A-level only), 1.8.5 Trigonometric identities, 1.8.6 Compound and double angle formulae (A-level only), 1.8.7 Solving trigonometric equations, 1.8.8 Proofs with trigonometric identities, and 1.8.9 Trigonometry in context. Each one has a worked solution and a mark scheme showing where the marks go.