Card 1 of 20
State the sine double-angle formula.
A
Double-angle formulae are obtained by substituting A=B=θ\boxed{A=B=\theta}A=B=θ into the addition formulae.
B
Using cos2θ=2cos2θ−1\cos 2\theta=2\cos^2\theta-1cos2θ=2cos2θ−1 gives 1+cos2θ=2cos2θ1+\cos 2\theta=2\cos^2\theta1+cos2θ=2cos2θ.
C
sin2θ=2sinθcosθ\sin 2\theta=2\sin\theta\cos\thetasin2θ=2sinθcosθ
D
cos2θ−sin2θ\cos^2\theta-\sin^2\thetacos2θ−sin2θ
Card 1 of 20
3.4.5 Trigonometry (A-level only) Flashcards
20 flashcards on CCEA A Level Maths 3.4.5 Trigonometry (A-level only): the key formulae, methods and definitions you need to recall for AS 1, AS 2, A2 1 and A2 2.