Answer:
X = 48
Explanation:
When you type sin(42) in your calculator it will give you something around 0.669.
If you try reverse sinus sin-1(0.669) it will give you 42.
Therefore you can say that:
Cos(x) = 0.669
So you can reverse the cos to get your answer
Cos-1(0.669) = 48
Or
Cos-1 (sin(42))