IDNLearn.com provides a seamless experience for finding and sharing answers. Discover reliable answers to your questions with our extensive database of expert knowledge.

Find the volume of the frustrum of the right circular cone generated by rotating the line y = 3x+1 about the x-axis between x = 0 and x = 2.

Sagot :

Answer:

38π cubic units

Step-by-step explanation:

The volume V = ∫₀²πy²dx  

Since y = 3x + 1, dy = 3dx ⇒ dx = dy/3

So, when x = 0, y = 3(0) + 1 = 0 + 1 = 1

when x = 2, y = 3(2) + 1 = 6 + 1 = 7

So, changing the variable to y and the limits of integration from y = 1 to y = 7, we have

V = ∫₀²πy²dx

V = π∫₁⁷y²dy/3

V = π[y³/3]₁⁷/3

V = π[y³]₁⁷/9

V = [7³ - 1³]π/9

V = [343 - 1]π/9

V = 342π/9

V = 38π cubic units