I have a problem I need help with. The problem is asking me to find the volume of a tall soft drink cup which has a top radius of 1.5, height of 8, and bottom radius of 1. The problem wants me to give the answer in fraction form?
Weird-looking cup! That drawing is to scale. Oh well!
The formula for the volume of a paper cup (or a lamp shade if upside down)
is found at this site:
http://calculus-geometry.hubpages.com/hub/Volume-of-a-Truncated-Cone-Conical-Frustum#
where a and b are the two radii, it doesn't matter which is which.
And h = the height.
Since you want fraction form, we'll change the decimal 1.5 to a fraction
And we'll use the approximate fraction for which is
Invert the 3 and multiply. Simplify the parentheses on the right.
Get LCD of 4 in the parentheses on the right:
The 4 on the bottom of the second fraction goes into the 176
on the top of the first fraction 44 times. So we have:
Multiply tops and bottoms:
, the fraction form
Edwin