Given that θ\thetaθ is a small angle, find an approximation for cos(3θ)\cos(3\theta)cos(3θ).
Select the correct answer from the options below:
1−9θ221 - \frac{9\theta^2}{2}1−29θ2
1−3θ221 - \frac{3\theta^2}{2}1−23θ2
3−3θ223 - \frac{3\theta^2}{2}3−23θ2
1−9θ21 - 9\theta^21−9θ2
Practise Edexcel A Level Maths 5.5 Small Angle Approximations with exam-style questions for A Level Maths. 25 questions, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.