Aregion r is revolved about the x-axis. the volume of the resulting solid could (in principle) be found by using the disk/washer method and integrating with respect to ▼ x y or using the shell method and integrating with respect to ▼

Solution in explanation given below.

Step-by-step explanation:

Consider a region R revolved about the x-axis

The volume of the resulting solid using the shell method is given by:

V =

where p(y) ≥ q(y) for c ≤ y ≤ d

Hence, the solutions of the answers are filled with x and y respectively.

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6