Tentukan nilai bentuk trigonometri berikut. 1. Sin 75° Cos 280° tan 135°/ cos 345° sin 190° cotan 225° 2. Sin 780° + cos 330° + tan 150°

1.
[tex] \frac{ \sin(75) \times \cos(280) \times \tan(135) }{ \cos(345) \times \sin(190 ) \times \cot(225) } \\ = \frac{( \sin(45) \cos(30) + \sin(30) \cos(45))( \cos(280))( \tan(135) ) }{( \cos(300) \cos(45) - \sin(300) \sin(45))( - \cos(280) )( \frac{1}{ \tan(225) } ) } \\ = \frac{( \frac{ \sqrt{2} }{2} \times \frac{ \sqrt{3} }{2} + \frac{1}{2} \times \frac{ \sqrt{2} }{2})( - 1) }{ (\frac{1}{2} \times \frac{ \sqrt{2} }{2} - \frac{ - \sqrt{3} }{2} \times \frac{ \sqrt{2} }{2})( - 1)( \frac{1}{1} ) } = \frac{ \frac{ \sqrt{6} + \sqrt{2} }{4} }{ \frac{ \sqrt{2} + \sqrt{6} }{4} } = 1[/tex]

2.
[tex] \sin(780) + \cos(330) + \tan(150) \\ = \sin(60) + \cos(30) + ( - \tan(30)) \\ = \frac{ \sqrt{3} }{2} + \frac{ \sqrt{3} }{2} - \frac{ \sqrt{3} }{3} = \sqrt{3} - \frac{ \sqrt{3} }{3} \\ = \frac{2 \sqrt{3} }{3} [/tex]