Answer:
x = 22
Step-by-step explanation:
Let's say that a & b are complementary angles...
Then cos a = sin b
We can also write sin(3x) as ,
[tex] \sin(3x) = \cos(90 - 3x) [/tex]
Substituting the value of sin(3x) in the question ,
[tex] \cos(x + 2) = \cos(90 - 3x) [/tex]
Cancelling cos from both the sides gives us -
[tex]x + 2 = 90 - 3x\\ [/tex]
Solving this eqn , x = 22