Friday

April 18, 2014

April 18, 2014

Posted by **melinda** on Sunday, January 15, 2012 at 12:45pm.

Find the ratio of the surface area of a cylinder to the volume of the cylinder if the height remains at 10 cm. Simplify this ratio and let f(x) = the simplified ratio. Let r be the radius of the cylinder.

a) Find the average rate of change as the radius increases from 2 to 5 cm.

Volume:πr^2

SA: 2π^2 + 2πrh

- Math -
**Reiny**, Sunday, January 15, 2012 at 4:36pmBoth of your formulas are incorrrect

Vol of cylinger = πr^2 h

SA = 2πr^2 + 2πrh

so when h = 10,

SA/V = (2πr^2 + 20πr)/(10πr^2

= (r + 10)/(5r)

f(r) = (r+10)/(5r)

f(2) = 12/10 = 6/5 = 1.2

f(5) = 15/25 = .6

avg rate of change = (.6-1.2)/(5-2) = -.2

**Related Questions**

Precalculus - How do you setup the equation for this? Thanky ou! Find the ratio ...

math - How would I setup the equation for the perimeter and area of a similar (...

Physics Lab - (a) For the rotating mass in the lab setup by what ratio will the ...

math - setup an equation or expression to model the situation below: find the ...

Math - Two rectangles are similar and the ratio of their sides is 1: 4. Find ...

math - The ratio of the radii of two circles is 2:3. find the ratio of their ...

math - The ratio of the radii of two circles is 2:3. Find the ratio of their ...

7th grade math - find a ratio equivalent to the ratio 7 over 9 then use the ...

calculus - what is the equation for taking the derivitive of -x^2+x just ...

math - setup an equation or expression to model the situation: a rectangle that ...