1. ## How do i add these formula

2. Using compound angle formula show that

Sin(A-B) + Sin(A+B) = 2Sin A Cos B

Here are the equations...(I know i need to add them but how ?)

[IMG]file:///C:/DOCUME%7E1/CHRISH%7E1/LOCALS%7E1/Temp/moz-screenshot-7.jpg[/IMG]
Sin(A-B) = Sin A cos B - Sin B Cos A
Sin(A+B) = Sin A Cos B + Sin B Cos A

2. Originally Posted by duckegg911

2. Using compound angle formula show that

Sin(A-B) + Sin(A+B) = 2Sin A Cos B

Here are the equations...(I know i need to add them but how ?)

[IMG]file:///C:/DOCUME%7E1/CHRISH%7E1/LOCALS%7E1/Temp/moz-screenshot-7.jpg[/IMG]
Sin(A-B) = Sin A cos B - Sin B Cos A
Sin(A+B) = Sin A Cos B + Sin B Cos A
Hi duckegg911,

This seems pretty straightforward to me.

$\sin(A+B) + \sin (A-B)=\sin A \cos B - \sin B \cos A + \sin A \cos B + \sin B \cos A=$

The $\sin B \cos A$ terms cancel out.

$2 \sin A \cos B$