Answer:
0.2588
Step-by-step explanation:
(√3 - 1) / 2√2.
Using the compound angle identity
cos(A + B) = cosA cosB - sinA sinB:-
cos 75
= cos (45 + 30)
= cos 45 cos 30 - sin 45 sin 30
= 1 / √2 * √3/2 - 1 / √2 * 1 / 2
= √3 / 2√2 - 1 / 2√2
= (√3 - 1) / 2√2.
