Answer :

Given

[tex]\tan3x=\frac{\sin6x}{1+\cos6x}[/tex]

Find

Find which identities used to show

[tex]\tan3x=\frac{\sin6x}{1+\cos6x}[/tex]

Explanation

as,, we use

[tex]\begin{gathered} \sin2x=2\sin x\cos x \\ \cos2x=2\cos^2x-1 \end{gathered}[/tex]

so ,

[tex]\begin{gathered} \sin(6x)=2\sin(3x)\cos(3x) \\ \cos(6x)=2\cos^2(3x)-1 \end{gathered}[/tex]

now, substitute the values on the left side

[tex]\begin{gathered} \frac{2\sin(3x)\cos(3x)}{1+(2\cos^2(3x)-1)} \\ \\ \frac{\begin{equation*}2\sin(3x)\cos(3x)\end{equation*}}{1+2\cos^2(3x)-1} \\ \\ \frac{2\sin(3x)\cos(3x)}{2\cos^2(3x)} \\ \\ \frac{\sin(3x)}{\cos(3x)} \\ \\ \tan(3x) \end{gathered}[/tex]

Final Answer

Therefore . we use 3 identities which are A , B and D