Tentukan nilai dari 1/2 sin (-300°) + cos45° - cos225° =

[tex] \frac{1}{2} \sin( - 300) + \cot(45) - \cos(225) \\ \frac{1}{2} \sin(60) + \cos(45) - ( - \cos(45) ) \\ \frac{1}{2} \times \frac{1}{2} \sqrt{3} + \frac{1}{2} \sqrt{2} + \frac{1}{2} \sqrt{2} \\ \frac{1}{4} \sqrt{3} + \sqrt{2} \\ \frac{1}{4} \sqrt{3} + \frac{4}{4} \sqrt{2} \\ \frac{ \sqrt{3} + 4 \sqrt{2} }{4} [/tex]