[tex]\bf \textit{Double Angle Identities}
\\\\
sin(2\theta)=2sin(\theta)cos(\theta)
\\\\
cos(2\theta)=
\begin{cases}
cos^2(\theta)-sin^2(\theta)\\
1-2sin^2(\theta)\\
2cos^2(\theta)-1
\end{cases}\\\\
-------------------------------\\\\
sin(2x)-cos(2x)\implies 2sin(x)cos(x)~~~~-~~~~2cos^2(x)-1
\\\\\\
\stackrel{common~factor}{2cos(x)}[sin(x)~~-~~cos(x)]-1[/tex]
