Ceiling Function is the least integer that is greater than or equal to x.
No, they are both incorrect by my understanding of your question use the Pythagorean theorem a^2 + b^2 =c^, therefore, 7^2 +x^2 = 13^2 or 49+x=169 then solve normally 169-49=120 √120 =5
The answer is 5
The radius is half the diameter, so the formula would be r=d divided by 2
1) a=5+√29 or a=5−√29
2) x=1 or x=−21
3) x=4 or x=6
4) x=9+√146 or x=9−√146
Hopefully that helps you ❤