Answer:
OKAY I WAS STRESSING FOR A QUICK MINUTE THINKING I WAS GETTING SOMETHING WRONG BUT THINK THE ANSWER IS CORRECT
So Cos0= 15/64 (SIMPLIFIED) or in decimal form 0.234375
Explanation:
7/8² is 49/64 or (in decimal form) 0.765625
1 - 0.765625 = 0.234375