# A Sine/Cosine Identity

A Sine/Cosine Identity

This Demonstration looks at the trigonometric identity . We plot the functions (red curves), (orange curves), and compare the plots of the functions (black, on the left) and (black, on the right); when , they are the same.

sin(2θ)=2sin(θ)cos(θ)

sin(Ax)

cos(Bx)

2sin(Ax)cos(Bx)

sin((A+B)x)

A=B