Evaluate −2x^3+4y^2 when x=1 and y=5

To answer this question, you need to know the formula for calculating the volume of cone and cylinder. The formula should look like this:

cone volume: π * r^2 * h/3
cylinder volume: π * r^2 * h

Now if you compare both of them with information that the radius and height is same, then the cone:cylinder volume ratio would be:

Cone volume/cylinder volume=
π * r^2 * h/3 / π * r^2 * h= 1/3

Cone volume is 1/3 of cylinder volume