# Trigonometric Identity - Product to Sum 1/2

**Product to Sum Trigonometric Identity Involving (sin(a)*sin(b) and cos(a)*cos(b))**

Video Tutorial: Writing a product of two sine functions and the product of two cosine functions as a sum or difference.

Last updated Aug 14, 2013,
created Aug 14, 2013

Error occurred while adding this resource to your favourites list. Please try again later.

### Ages

### Categories

## Related resources

## Popular resources by this author

## Top premium lessons

## New lessons

- 150 SAT LEVEL 2 (Subject Test) Math Questions
- Quadratic Formula - cut out and prove
- Core 2 Exponentials and logarithms introduction and solving equations
- Recognising Graphs from Equations
- MAT test preparation/revision
- Radioactive dating of meteorites (Post-16)
- C2 Circles and their formulae
- Exact Value Trigonometry
- IB Maths HL Calculus Option Notes (100 Pages)
- Calculus (AQA FP1)

## Top free lessons

- A Level Maths Assessments - C1-C4, D1, D2, FP1, FP2, M1, M2, S1, S2
- Maths Core 3 - Set of lesson Powerpoints
- Maths Further Pure 1 - Set of lesson powerpoints
- Maths Core 1 - Set of lesson powerpoints
- Maths Core 2 - Set of lesson powerpoints
- Maths Core 4 - Set of Lesson Powerpoints
- Transformation of Graphs
- Core 1 (Edexcel) Revision
- A level Maths: Transformations of curves worksheet
- Binomial Expansion Powerpoint

## Recently updated

- 150 SAT LEVEL 2 (Subject Test) Math Questions
- C4 - Chapter 6 - Integration
- Quadratic Formula - cut out and prove
- Core 2 Exponentials and logarithms introduction and solving equations
- Recognising Graphs from Equations
- Complete Conics: Notes, Examples and Tests
- FP2 - Chapter 6 - Maclaurin/Taylor Series
- Parametric Equations to Cartesian Equations Jigsaw
- MAT test preparation/revision
- Core Mathematics 1 PowerPoint