The base of a solid is the triangular region in the first quadrant bounded by the graph of y=4-2x and the x- and y- axes. For the solid, each cross section perpendicular to the x-axis is a square. What is the volume of solid?
A. 4
B. 8
C. 32/3
D. 64/3



Answer :

To find the volume of the solid, we need to integrate the area of each cross section perpendicular to the x-axis. Since each cross section is a square, the area of each cross section will be the side length squared.

To determine the side length of each square, we need to find the length of the base of the square at each x-coordinate. This can be done by finding the y-coordinate on the graph of y=4-2x.

Let's set up the integral to find the volume:

∫[a,b] (4-2x)^2 dx

To find the limits of integration, we need to determine the x-values where the graph of y=4-2x intersects the x-axis. Setting y=0, we get:

0 = 4-2x
2x = 4
x = 2

So, the limits of integration are from x=0 to x=2.

Now, let's evaluate the integral:

∫[0,2] (4-2x)^2 dx

= ∫[0,2] (16 - 16x + 4x^2) dx

= [16x - 8x^2 + (4/3)x^3] evaluated from x=0 to x=2

= (16(2) - 8(2)^2 + (4/3)(2)^3) - (16(0) - 8(0)^2 + (4/3)(0)^3)

= (32 - 32 + (32/3)) - (0 - 0 + 0)

= 32/3

Therefore, the volume of the solid is 32/3 cubic units.

So the answer is C. 32/3.