40 POINTS!!!! PLEASE HELP!!!!

Answer:
cos(2x) = √17/17
Step-by-step explanation:
Use the Pythagorean Theorem to find the sides of the triangle, then use trigonometric identities??
Answer:
cos(2x) = √17/17
Step-by-step explanation:
Use the Pythagorean Theorem to find the sides of the triangle, then use trigonometric identities