im lost when it comes to graphs?

Question

The volume of a cylinder (think about the volume of a can) is given by V = πr2h where r is the radius of the cylinder and h is the height of the cylinder. Suppose the volume of the can is 100 cubic centimeters.
graph this function.

Answer 1

for graphing purposes, lets put it like this

V = pi * x^2 * y

100 = pi * x^2 * y

divide both sides by pi * x^2

y = 100/(pi * x^2)

so this would look like

h = 100/(pi * r^2)

or as a function, it would be

h(r) = 100/(pi * r^2)

and for graphing, it would be

f(x) = 100/(pi * x^2)

for a graph, go to http://www.calculator.com/calcs/GCalc.html

type in only 100/(pi * x^2), then click enter on the keyboard. and only worry about the positive "x" side since you can't have negative radius.