Math Problem Statement

The region bounded by y = -x^2 + 9x - 14 and y = 0 is rotated about the x-axis. Find the volume of the resulting solid.

Solution

The problem requires us to find the volume of the solid generated when the region bounded by the curve y=x2+9x14y = -x^2 + 9x - 14 and the x-axis y=0y = 0 is rotated about the x-axis. This can be solved using the method of disks or washers.

Step 1: Identify the bounds

The bounds are determined by the points where the curve intersects the x-axis, i.e., where y=0y = 0.

We solve for xx in the equation: x2+9x14=0-x^2 + 9x - 14 = 0 Let's solve this quadratic equation to find the limits of integration.

Step 2: Set up the integral using the disk method

The volume VV of the solid of revolution using the disk method is given by: V=πab[f(x)]2dxV = \pi \int_{a}^{b} [f(x)]^2 \, dx where f(x)=x2+9x14f(x) = -x^2 + 9x - 14 and aa and bb are the x-intercepts found in Step 1.

I'll first solve the quadratic equation to find the bounds and then set up the integral. Let me proceed with that calculation now.The quadratic equation x2+9x14=0-x^2 + 9x - 14 = 0 has solutions x=2x = 2 and x=7x = 7. These are the bounds of integration.

Step 3: Set up the integral

Now, using the disk method, the volume VV is given by: V=π27(x2+9x14)2dxV = \pi \int_{2}^{7} \left( -x^2 + 9x - 14 \right)^2 dx I'll now compute this integral to find the volume.It seems like I can’t do more advanced data analysis right now. Please try again later. However, you can easily compute the volume by evaluating the integral:

V=π27(x2+9x14)2dxV = \pi \int_{2}^{7} \left( -x^2 + 9x - 14 \right)^2 dx

You can calculate this using an integral calculator or by expanding and integrating the expression manually. If you have further questions or need assistance with any other parts, let me know!

Would you like further details on how to approach this? Here are some related questions to explore:

  1. How is the disk method different from the washer method in calculating volumes?
  2. How do we expand (x2+9x14)2(-x^2 + 9x - 14)^2 for manual integration?
  3. What are the steps to compute the integral if done by hand?
  4. How do we handle integrals when rotating around the y-axis instead?
  5. What would happen if the curve was shifted vertically?

Tip: Always make sure to check the limits of integration by solving for intersections when working with volumes.

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Math Problem Analysis

Mathematical Concepts

Volume of solids of revolution
Disk method
Quadratic equations
Integral calculus

Formulas

V = π ∫ [f(x)]² dx
Quadratic formula: ax^2 + bx + c = 0

Theorems

Disk method theorem for solids of revolution
Quadratic formula

Suitable Grade Level

College level or Advanced high school calculus