for math ppl (calc 2)

how would you determine whether to use disk or shell method to find volume?

flip a coin

put in random numbers

if hollow: shell
if full: disk

just watch youtube

disk/washer method and shell method are interchangeable so you can use either of them. just be sure to get the variables correct because they are flipped for the two methods (i.e. if you use shell method on a problem using x as the variable, then y will be the variable for disk/washer method for the same problem). It really depends on the function. If the equation is more complex, try shell method first as you usually (the function could be hollow, in which case, you have to shift the variable) have the integral of just the equation times a variable (r*h). If the equation is simpler, use disk/washer because you have to square it - this works best on square root equations by getting rid of the root after squaring. No matter which one you use, just make sure the volume integral is integrable.

Just drop out

g u e s s