Home Back

Finding Volume with Integrals

Volume by Revolution Formula (Disk Method):

\[ V = \int_{a}^{b} \pi \times [f(x)]^2 \, dx \]

e.g., x^2, sin(x), etc.

Unit Converter ▲

Unit Converter ▼

From: To:

1. What is Volume by Revolution?

Definition: This method calculates the volume of a solid formed by rotating a function around the x-axis between two points.

Purpose: It's used in calculus and engineering to determine volumes of complex shapes defined by mathematical functions.

2. How Does the Disk Method Work?

The calculator uses the formula:

\[ V = \int_{a}^{b} \pi \times [f(x)]^2 \, dx \]

Where:

Explanation: The method sums up infinitely thin circular disks along the axis of rotation to compute the total volume.

3. Importance of Volume Calculation

Details: Accurate volume calculations are essential in engineering design, fluid dynamics, and manufacturing processes.

4. Using the Calculator

Tips: Enter the function (e.g., x^2, sin(x), etc.), integration limits (a and b). The upper limit must be greater than the lower limit.

5. Frequently Asked Questions (FAQ)

Q1: What functions can I use?
A: The calculator supports standard mathematical functions - polynomials, trigonometric, exponential, etc.

Q2: What if I get an error?
A: Check your function syntax and ensure b > a. Some complex functions may require numerical methods.

Q3: Can I rotate around the y-axis instead?
A: Yes, but you would need to use the shell method or express x as a function of y.

Q4: How accurate are the results?
A: Accuracy depends on the numerical integration method used, typically very precise for most applications.

Q5: What about solids with holes?
A: For washers, subtract the inner radius function squared from the outer radius function squared.

Finding Volume with Integrals© - All Rights Reserved 2025