need (working and explanation) thank you!!

1. On a circle, describe the relationship between an interior angle and the arc length subtended by that angle.
2. With respect to the unit circle, describe the geometric meaning of arccos(x) both in terms of an angle and an arc length.
3. Represent this arc length as an integral. Then, use this integral and the Fundamental Theorem of Calculus to compute the derivative of arccos(x).
4. Do the same for arcsin(x) - describe the geometric meaning in terms of an angle and arc length, represent the arc length as an integral, then compute the derivative of arcsin(x).