Question

given that cos (A + B) = cos A.cos B - sin A.sin B. Find the value of cos 75°.​

Answer 1

ANSWER:

$\cos(75</u></strong><strong><u>°</u></strong><strong><u>) = \frac{\sqrt{3} - 1}{2 \sqrt{2} }$

Answer 2

Answer:

cos 75°=

cos (90°-A)

cos (90°-75°)

cos (15°)

Therefore, the answer is cos15°

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