Addition Formula for Sine
Addition Formula for Sine
The addition formula for sine states that .
sin(A+B)=sin(A)cos(B)+cos(A)sin(B)
All triangle hypotenuses in the above figures are of unit length, so that the sines and cosines are simply the adjacent or opposite sides of their triangles relative to the angles , , or . The gray areas on the left and right equal the left and right sides of the formula.
A
B
A+B
When , the formula reduces to the double-angle formula .
A=B
sin(2A)=2sin(A)cos(A)
External Links
External Links
Permanent Citation
Permanent Citation
Chris Boucher
"Addition Formula for Sine"
http://demonstrations.wolfram.com/AdditionFormulaForSine/
Wolfram Demonstrations Project
Published: February 15, 2008