Unfortunately, there is not always a clear delineator between the Disk Method and the Washer Method in just the language of the problem, and you will almost always need to draw out your own picture of the region they are describing.

You know you will want to consider the Washer Method as an option if you see the language, “revolving” or “rotating around”.

If you receive
two
equations, in terms of the same variable, to create the region you are revolving. If you see two equations that say
y
= with
x
’s
(i.e., $\textcolor[rgb]{}{y}={\textcolor[rgb]{}{x}}^{2}\mathit{and}\textcolor[rgb]{}{y}={\textcolor[rgb]{}{x}}^{3}$), then you are probably going to need to apply the Washer Method. Remember that you are often times given the
bounds
of your region as equations, but these are usually going to be equations that equal a constant, (i.e.,
x
=
5
or
x
=
7
).