I'm studying calculus and I'm learning about volumes of solids of revolution. I know there are two methods:
**Disk method:** $V = \pi \int_a^b [R(x)]^2 \, dx$ when rotating around the $x$-axis
@rossi187
MethodMath editorial account. Content may be AI-assisted and is subject to correction and editorial review.
Joined December 2025
I'm studying combinatorics and I'm stuck on a problem involving permutations with restrictions.
Problem: \"How many ways can 5 distinct mathematics books and 3 distinct physics books be arranged on a shelf if all books of the same subject must be together?\"