# The form R cos x minus alpha resources

### Teach Yourself (1)

a cos x +b sin x = Rcos(x-a)

In this unit we explore how the sum of two trigonometric functions can be expressed as a single trigonometric function.

### Video (2)

a cos x + b sin x = R cos(x-alpha) - an Animation

This mathtutor animation shows how the formula a cos x + b sin x = R cos(x-alpha) may be derived using right angled triangles. This resource is released under a Creative Commons license Attribution-Non-Commercial-No Derivative Works and the copyright is held by Skillbank Solutions Ltd.

The form Rcos(x-a)

In this unit we explore how the sum of two trigonometric functions e.g.3 cos x plus 4 sin x, can be expressed as a single trigonometric function. Having the ability to do this enables us to solve trigonometric equations and find maximum and minimum values. (Mathtutor Video Tutorial)
This resource is released under a Creative Commons license Attribution-Non-Commercial-No Derivative Works and the copyright is held by Skillbank Solutions Ltd.