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## Integral Calculus

### Unit 3: Lesson 9

Volume: disc method (revolving around x- and y-axes)

# Disc method: revolving around x- or y-axis

AP.CALC: CHA‑5 (EU), CHA‑5.C (LO), CHA‑5.C.1 (EK)
You might need: Calculator

## Problem

Let R be the region in the first quadrant enclosed by the x-axis, the y-axis, the line y, equals, 2, and the curve y, equals, square root of, 9, minus, x, squared, end square root.
A solid is generated by rotating R about the y-axis.
What is the volume of the solid?
Give an exact answer in terms of pi.
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