Answer:
3/5
Step-by-step explanation:
We can find ∅ by using the tangent function since we have the opposite and adjacent sides of ∅.
tan(∅)=1/2
tan^-1(tan(∅))=tan^-1(1/2)
∅=26.57
Since we are looking for cos(2∅), then we have cos(2(26.57))=cos(53.14)≈0.6
So the exact value is 3/5