Given that θ \theta\,θ is small, use the small angle approximation of cosθ \cos \theta\,cosθ to show that
3cos(2θ)+cos2(θ)≈4−7θ2+0.25θ4 3 \cos(2\theta) + \cos^2(\theta) \approx 4 - 7\theta^2 + 0.25\theta^4 3cos(2θ)+cos2(θ)≈4−7θ2+0.25θ4Hence find an approximation of 3cos(2θ)+cos2(θ)3 \cos(2\theta) + \cos^2(\theta)3cos(2θ)+cos2(θ) when θ=4∘\theta = 4^\circθ=4∘
Calculate the percentage error in your approximation
