Question

Given that cos (A - B) = cos A cos B + Sin A Sin B, find the value of cos 15° taking A = 45°
and B = 30°
please need the ans of this one...​

Answer 1

Step-by-step explanation:

cos(45-30)=cos45×cos30+sin45-sin30

cos 15= 1/√2 × √3/2 + 1/√2 × 1/2

cos15=√3+1 / 2√2