Question

If sin a = 7/25, cos a = 24/25, sin b = 3/5 and cos b= 4/5, find cos (a-b)

Answer 1

`cos(a-b) = (117)/(125)`

Explanation:

Explanation

Given that

`sina = (7)/(25) , cos a = (24)/(25) , sinb =(3)/(5) and cosb =(4)/(5)`

Cos(a-b) = cosa cosb + sina sinb

`cos(a-b) = (24)/(25) (4)/(5) +(7)/(25) (3)/(5)`

`cos(a-b) = (96)/(125) +(21)/(125) = (117)/(125)`

Final answer:-

`cos(a-b) = (117)/(125)`