For questions 8, 9, 10: Note that x² + y2 12 is the equation of a circle of radius 1. Solving for y we have y=√1-22, when y is positive. 8. Compute the length of the curve y = √1-2 between z = 0 and 2 = 1 (part of a circle.) 9. Compute the surface of revolution of y= V1-² around the z-axis between z=0 and = 1 (part of a sphere.)