## How do you do the washer method?

In the above figure, each slice has the shape of a washer so its area equals the area of the entire circle minus the area of the hole. where R is the outer radius (the big radius) and r is the radius of the hole (the little radius). Multiply this area by the thickness, dx, to get the volume of a representative washer.

## How do you rotate a function around the Y axis?

The disk method is predominantly used when we rotate any particular curve around the x or y-axis. Suppose a function x = f(y), which is rotated about the y-axis. V = π ∫dc [f(y)]2dy. The cross-section perpendicular to the axis of revolution has the form of a disk of radius R = f(y).

**What is the washer method in calculus?**

The washer method is a fairly straightforward method for finding the volume between two functions that are rotated around the x-axis. The formula involves the area of a circle and is easy to use. If two functions intersect each other, we need to find where they intersect by setting them equal to each other and solving.

**How do you tell if it’s a washer or disk?**

The only difference here is whether that area is bounded by two functions (washer) or one function and the x-axis itself (disk). If the hole in the center of your washer is so small it doesn’t exist, then you just have a disk.

### When should I use the washer method?

The Washer Method is used when the rectangle sweeps out a solid that is similar to a CD (hole in the middle). And finally, the Shell Method is used when the rectangle sweeps out a solid that is similar to a toilet paper tube.

### When can I use the washer method?

**How do you reflect over the y-axis?**

The rule for a reflection over the y -axis is (x,y)→(−x,y) .

**How do I know if I have washer or disk?**

#### What is washer method used for?

#### Is disk and washer method the same?

Washers use the same method as disks but computer the volume when the figure has a hollow parrallel along the x-axis. The calculation is outer volume minis inner volume to give the volume between.

**What is the volume of disc?**

The volume of each disk is πr2Δx, where r is the radius of the specific disk and Δx is its height. There are two crucial steps to the problem.

**What is the equation for the washer method?**

The formula for the area of a circle is pi * r^2. So, the area of the washer is pi * R^2 – pi * r^2, where the R is the outer radius and r is the inner radius. Plugging the functions into our respective radii will give us a formula for the washer method we can use.

## How do you calculate the volume of a washer?

How to Calculate the Tub Volume or Capacity of a Washer Make all measurements in feet. Measure the radius of the tub; from the center of the tub to the outside wall of the tub. Using the formula, multiply the radius by the radius; note this is not the same as multiplying the radius by two. Multiply the radius squared from step three above by pi (3.14).

## What is the method of washers?

Washer Method. A technique for finding the volume of a solid of revolution. The washer method is a generalized version of the disk method. Both the washer and disk methods are specific cases of volume by parallel cross-sections.