If cos (x + 25)o = sin 45o, find the value of x
A
20
B
30
C
45
D
60
Verified Correct Answer: A.
Step-by-Step Mathematical Solution
cos(x + 25o) = sin 45o
using cos \(\theta\) = sin(90 - \(\theta\))
cos(x + 25o) = cos(90 - 45)
cos(x + 25o) = cos 45
x + 25 = 45
x = 45 - 25
x = 20o
Source: Myschool Past Questions Archive (Record #36364)