Card 1 of 22
Which substitutions turn compound angle identities into double angle identities?
A
Set A=θA=\thetaA=θ and B=θB=\thetaB=θ.
B
12sin2θ\frac12\sin 2\theta21sin2θ
C
The tangent double angle identity is tan2θ=2tanθ1−tan2θ\boxed{\tan 2\theta=\frac{2\tan\theta}{1-\tan^2\theta}}tan2θ=1−tan2θ2tanθ, where both sides are defined.
D
The first cosine double angle form is cos2θ=cos2θ−sin2θ\boxed{\cos 2\theta=\cos^2\theta-\sin^2\theta}cos2θ=cos2θ−sin2θ.
Card 1 of 22
1.7.19 Double angle identities (A-level only) Flashcards
22 flashcards on OCR (MEI) A Level Maths 1.7.19 Double angle identities (A-level only): the key formulae, methods and definitions you need to recall for Component 01, Component 02 and Component 03.