Please help 15 points!

The last time i bought this product , it cost $20.00 but it looks like it cost 29. 60 today? what is the increase

Choose the correct slope of the line that passes through the points (1, -3) and (3, -5)

Determine whether the following statements are true and give an explanation or counterexample. bold a. when using the shell method, the axis of the cylindrical shells is parallel to the axis of revolution. bold b. if a region is revolved about the y-axis, then the shell method must be used. bold c. if a region is revolved about the x-axis, then in principle it is possible to use the disk/washer method and integrate with respect to x or the shell method and integrate with respect to y.