A polarizing lens reduces the intensity of an incoming light beam according to the model
L(θ)=12cos2θ L(\theta) = 12\cos^2 \theta L(θ)=12cos2θwhere LLL is the transmitted intensity in candelas and θ\thetaθ is the orientation angle of the lens in radians.
Determine all values of θ\thetaθ in the interval 0≤θ≤2π0 \le \theta \le 2\pi0≤θ≤2π for which the transmitted intensity is exactly 999 candelas. Give your answers as exact multiples of π\piπ.
5 exam-style questions on Edexcel A Level Maths 5.4 Solving Trigonometric Equations. Each one has a worked solution and a mark scheme showing where the marks go.