This was written to be used a teacher-led resource. It was written using the enhanced features of PowerPoint 2003, therefore the full effect of the lesson can only be seen using PowerPoint 2003 (or PowerPoint XP). If you are running Office 2000, you can download a PowerPoint 2003 Viewer from Microsoft and this will enable you to run the file as it was intended. In response to the feedback I’ve received, I have removed the security on the original file to enable it to be saved to an external source (flash drive, etc).

This is a PowerPoint Presentation of a "proof" of sin (A+B) = sinA cosB + sinB cosA The teacher should provide his/her own commentary as he/she progresses through the presentation with the class.