Answer:
\(\frac{1-\sqrt{3} }{4}\)
Step-by-step explanation:
By using the sum and difference identities of cos 225 and cos 75 you can find their exact values are \(-\frac{\sqrt{2} }{2}\) and \(\frac{\sqrt{6}-\sqrt{2} }{4}\) respectively. Then, all you have to do is multiply the fractions together to get \(\frac{1-\sqrt{3} }{4}\).
