Find the volume of the solid whose base is the region in the first quadrant bounded by y=x^3, y=1, and the y axis whose cross sections perpendicular to the y axis are equilateral triangles.

The region in question is the set

or equivalently,

Cross sections are taken perpendicular to the y-axis, which means each section has a base length equal to the horizontal distance between the curve y = x³ and the line x = 0 (the y-axis). This horizontal distance is given by

y = x³   ⇒   x = ∛y

so that each triangular cross section has side length ∛y.

The area of an equilateral triangle with side length s is √3/4 s², so each cross section contributes an infinitesimal area of √3/4 ∛(y²).

Then the volume of this solid is

I've attached some sketches of the solid with 16 and 64 such cross sections to give an idea of what this solid looks like.

3,6 and 7.

step-by-step explanation:

a) unit place of 37 is 7

so the unit place of cube of 37 will be

7³= 343=3

the answer is 3.

b) unit place of 56 is 6, so the unit place of cube of 56 will be

6³= 216=6

the answer is 6.

c) unit place of 133 is 3, so the unit place of cube of 133 will be

3³= 27= 7.

the answer is 7.