Question

giventhat cos(a-b)= cosA cos B+sin A sin B. find the value of cos 15 by taking a=60 b=45​

Answer 1

Answer:

1 + root 3 / 2 root 2

Step-by-step explanation:

cos(60-45) =

cos60 cos 45 + sin 60 sin 45

1/2×1/root 2+root 3 / 2 ÷ 1/ root 2

1 / 2 root 2 + root 3 / 2 root 2

1 + root 3 / 2 root 2