tolong bantu no. 5 dan 11 pakai jalannya atau penyelesaian

[tex] \cos(x) = \sqrt{1 - \frac{8}{9} } = \frac{1}{3} \\ \sin(x + 30) = \frac{2}{3}\sqrt{2} . \frac{ \sqrt{3} }{2} + \frac{1}{3} . \frac{1}{2} = \frac{ \sqrt{6} }{3} + \frac{1}{6} = \frac{1}{6} (2 \sqrt{6} + 1)[/tex]
[tex] \sin( \frac{\pi}{4} + \alpha ) - \sin( \frac{\pi}{4} - \alpha ) = \\ \sin(45) \cos( \alpha ) + \cos(45) \sin( \alpha ) = \frac{1}{2} \sqrt{2} ( \sin( \alpha ) + \cos( \alpha ) ) \\\sin(45) \cos( \alpha ) - \cos(45) \sin( \alpha ) = \frac{1}{2} \sqrt{2} ( \cos( \alpha) - \sin( \alpha ) ) \\ \sqrt{2} \sin( \alpha ) [/tex]