Find arc length: y=2ln(sin(x/2)); pi/3 < x < pi I got the answer 2ln(1+sqrt(3)) while my classmate got 2ln(2+sqrt(3)) but neither of us are sure

In stepmber, daniel and justin opened a business. during their first three months of business, their average monthly profit was $51. if during their first month, they lost $29, and during their second month, they gained $115, what was their profit or loss for their third plzzz i will give you 299 points