Given that θ \theta\,θ is small,
4cos(θ)+cos2(2θ)≈5−6θ2+4θ4 4 \cos (\theta) + \cos^2 (2\theta) \approx 5 - 6\theta^2 + 4\theta^4 4cos(θ)+cos2(2θ)≈5−6θ2+4θ4Hence find an approximation of 4cos(θ)+cos2(2θ)4 \cos (\theta) + \cos^2 (2\theta)4cos(θ)+cos2(2θ) when θ=6∘\theta = 6^\circθ=6∘, giving your answer to 5 decimal places
278 exam-style questions on Edexcel A Level Maths Radians, covering 5.1 Radian Measure, 5.2 Arc Length, 5.3 Areas of Sectors and Segments, 5.4 Solving Trigonometric Equations, and 5.5 Small Angle Approximations. Each one has a worked solution and a mark scheme showing where the marks go.