7. Compute the length of the curve x = 2y³ + 1/(24y) from y = 1 to y = 3.

8. Find the length of y = ln (sec x) between x = 0 to x = /4.

9. Find the arc length of the curve y = ln x from x = 1 to x = 2.

10. Calculate the area of the surface of revolution obtained by revolving the curve x = 1/3 (y2 + 2)3/2 from y = 1 to y = 4 about the x-axis.