@@ 34,7 34,7 @@ Note that you must account for different axes of rotation, whether it be $x = 3$
### The Washer Method
The only difference between the washer and the disc method is that there is a **hole** to subtract. As such, the washer method is **the volume of the outside function subtracted by the inside function**.
$$Volume = \int_a^b\pi\ R(y)^2 dy - \int_a^b\pi\ r(y)^2 dy = \int_a^b \pi\$$
$$Volume = \int_a^b\pi\ R(y)^2 dy - \int_a^b\pi\ r(y)^2 dy = \int_a^b \pi$$
![Horizontal Washer Method](../assets/calculus/7-3_washer-method-horizontal.png)