# 6.2d4 Volume by Slicing. Revolve the area bound by the x-axis the curve f(x) = -(x - 1) 2 + 4 and the x-axis.

## Presentation on theme: "6.2d4 Volume by Slicing. Revolve the area bound by the x-axis the curve f(x) = -(x - 1) 2 + 4 and the x-axis."— Presentation transcript:

6.2d4 Volume by Slicing

Revolve the area bound by the x-axis the curve f(x) = -(x - 1) 2 + 4 and the x-axis

Make a paper thin slice at x = 2, we’ll say 0.01 units wide, calculate the volume of that slice.

Revolve the area bound by the x-axis the curve f(x) = -(x - 1) 2 + 4 and the x-axis Make a paper thin slice at x = 2, we’ll say 0.01 units wide, calculate the volume of that slice. V slice = πr 2 w V slice = π3 2 0.01 V slice = 0.09π

Revolve the area bound by the x-axis the curve f(x) = -(x - 1) 2 + 4 and the x-axis Make a paper thin slice at x = k, we’ll say 0.01 units wide, calculate the volume of that slice. V slice = πr 2 w r = y-value at the slice r = y = -(x – 1) 2 + 4, x = k… r = -(k – 1) 2 + 4 V slice = π(-(k – 1) 2 + 4) 2 0.01

Revolve the area bound by the x-axis the curve f(x) = -(x - 1) 2 + 4 and the x-axis Generically, we can say the volume of the slice at a given x value with width Δx is… V slice = π(-(x – 1) 2 + 4) 2 w If you make all of the slices infinitely thin and add them together, they become an integral distance in the direction that you are adding the slices

The same principal is true for other slice shapes. The area bounded by f(x) = -(x - 1) 2 + 4 is the base of an object. If you sliced this object vertically, it would have a cross sectional area of a square. Find the volume of the slice at x = 2 V = Lwh = b 2 w V = 3 2 * 0.01 V = 0.09

The area bounded by the x-axis and the curve f(x) = -(x - 1) 2 + 4 is the base of an object with a vertical cross section that is a square. Find the total volume

The area bounded by the x-axis and the curve f(x) = -(x - 1) 2 + 4 is the base of an object with a vertical cross section that is a semicricle. Find the total volume What is the volume of a single slice? Which terms becomes an integral distance as I make slices infinitely thin?

The area bounded by the x-axis and the curve f(x) = -(x - 1) 2 + 4 is the base of an object with a vertical cross section that is a semicricle. Find the total volume What’s constant? What does r = ?

The area bounded by the x-axis and the curve f(x) = -(x - 1) 2 + 4 is the base of an object with a vertical cross section that is an isosceles right triangle. Find the total volume What is the volume of a single slice? Which terms becomes an integral distance as I make slices infinitely thin?

The area bounded by the x-axis and the curve f(x) = -(x - 1) 2 + 4 is the base of an object with a vertical cross section that is an isosceles right triangle. Find the total volume What’s constant? What does b = ?

Similar presentations