If cos (x + 25)o = sin 45o, find the value of x

Correct Answer: Option A

Explanation

cos(x + 25^o) = sin 45^o
using cos (theta) = sin(90 – (theta))
cos(x + 25^o) = cos(90 – 45)
cos(x + 25^o) = cos 45
x + 25 = 45
x = 45 – 25
x = 20^o