jika cos beta = 5/13 dengan 270 < beta < 360 tentukan sin2beta cos 2 beta dan tan 2 beta tolong yahhhhh Nb = pake cara / rumus

[tex]
\cos{\beta}=\frac{5}{13}\Rightarrow\sin{\beta}=-\frac{12}{13}\\
\text{Selanjutnya, perhatikan bahwa}\\
\sin{2\beta}\cos{2\beta}\\
=2\sin{\beta}\cos{\beta}\cdot\left(\cos^2{\beta}-\sin^2{\beta}\right)\\
=2\cdot\left(-\frac{12}{13}\right)\cdot\frac{5}{13}\cdot\left(\left(\frac{5}{13}\right)^2-\left(-\frac{12}{13}\right)^2\right)\\
=-\frac{120}{169}\cdot\left(\frac{25}{169}-\frac{144}{169}\right)\\
=-\frac{120}{169}\cdot\left(-\frac{119}{169}\right)\\
=\frac{14280}{28561}\\
[/tex]