<em>x</em> ^2 + <em>y</em> ^2 = 9 => <em>y</em> = <em>y(x)</em> = ± √(9 - <em>x</em> ^2)
Each cross section would be a square with side length equal to the vertical distance between the upper and lower semicircles defined by <em>y(x)</em>, which is
√(9 - <em>x</em> ^2) - (- √(9 - <em>x</em> ^2)) = 2 √(9 - <em>x</em> ^2)
The area of each square section is the square of this length,
(2 √(9 - <em>x</em> ^2)) = 4 (9 - <em>x</em> ^2) = 36 - 4<em>x</em> ^2
We get the whole solid for -3 ≤ <em>x</em> ≤ 3, so integrating gives a volume of

ANSWER: 0.64 cents
EXPLANATION: 0.49x1.31 = 0.6419 = 0.64
Answer:
3
lazy approach was with a graphic plotting program, but you can also calculate it. with the pq-formula.
p = -6
q = 9
x = -p/2 +- sqrt( (p/2)² - q)
x = -(-6)/2 +- sqrt ( (-6/2)² - 9)
x = 3 +- sqrt(9-9)
x = 3 +- sqrt(0)
x = 3 +- 0
x = 3