How does sin(A+B)\sin(A+B)sin(A+B) expand?
A
sin(A+B)=sinAcosB+cosAsinB\sin(A+B)=\sin A\cos B+\cos A\sin Bsin(A+B)=sinAcosB+cosAsinB
B
The cosine-only double-angle form is cos2A=2cos2A−1\boxed{\cos2A=2\cos^2A-1}cos2A=2cos2A−1.
C
r=a2+b2r=\sqrt{a^2+b^2}r=a2+b2
D
cos2A=cos2A−sin2A\cos2A=\cos^2A-\sin^2Acos2A=cos2A−sin2A
1.8.6 Compound and double angle formulae (A-level only) Flashcards
Flashcards for AQA A Level Maths 1.8.6 Compound and double angle formulae (A-level only), covering the key formulae, methods and definitions you need to recall for Paper 1, Paper 2 and Paper 3. 21 cards, matched to the AQA A Level Maths (7357) specification. Recall questions account for roughly 50% of marks at A Level Maths, so these target the marks you can secure before the paper starts.