When a child is born, her grandfather decides to put $100 in an account that earns
interest. He plans to make no other deposits or withdrawals for 18 years. When
the child turns 18 years old, the money in the account will be a birthday gift.
The
grandfather is choosing between two options:

Option 1: grows by 10.5% each year

Option 2: grows by $20 each year

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.