Sin and Cos Definition:
\[r=1\]
Turn you head sideways to the right
to see the cos graph.
\[\sin(\theta)=\frac{y}{r}=y\] \[\cos(\theta)=\frac{x}{r}=x\]
Parity Identities:
Turn you head sideways to the right
to see the cos graph.
\[\sin(-\theta)=-\sin(\theta)\] \[\cos(-\theta)=\cos(\theta)\quad\]
Complementary Angle
Identities:
Turn you head sideways to the right
to see the cos graph.
\[\sin(\frac{\pi}{2}-\theta)=\cos(\theta)\] \[\cos(\frac{\pi}{2}-\theta)=\sin(\theta)\]
Supplementary Angle
Identities:
Turn you head sideways to the right
to see the cos graph.
\[\sin(\pi-\theta)=\sin(\theta)\quad\] \[\cos(\pi-\theta)=-\cos(\theta)\]
