Trigonometry
We are given the following condition:
sin (a) = cos (b)
Since both angles are acute, the following relationship must apply:
a = 90° - b
Both angles must be complementary
Substituting the values for each angle:
a = 5x - 2
b = 5x - 22
We have:
5x - 2 = 90 - (5x - 22)
Removing brackets:
5x - 2 = 90 - 5x + 22
Adding 5x:
5x - 2 + 5x = 90 + 22
Adding 2:
5x + 5x = 90 + 22 + 2
Simplifying:
10x = 114
Dividing by 10:
x = 114/10
x = 11.4
Correct choice: C)
