Formula for sin(A+B)
Introduction
What is the formula for sin(A+B)?
Is sin(A+B)=sin A + sin B?
This applet shows the formula for sin(A+B) and cos(A+B).
How to use the applet
Change angles A and B by pressing "+" and "-" buttons.
The lengths of three arrows appear by checking "Character" box.
You will understand the green arrow is the sum of the red
arrow and the blue arrow. That indicates the formula for sin(A+B).
Applet
Sum and Difference Formulas
sin(A+B)=sin A cos B + cos A sin B
sin(A-B)=sin A cos B - cos A sin B
cos(A+B)=cos A cos B - sin A sin B
cos(A-B)=cos A cos B + sin A sin B