Math Problem Statement

integrate g(x) = x/(2x^2 + 5) between 0 to 1

Solution

To solve the integral of g(x)=x2x2+5g(x) = \frac{x}{2x^2 + 5} from 0 to 1, we will follow these steps:

Step 1: Set up the integral

01x2x2+5dx\int_0^1 \frac{x}{2x^2 + 5} \, dx

Step 2: Use substitution

Let’s perform a substitution to simplify the integral. Define: u=2x2+5u = 2x^2 + 5 Now, compute dudu in terms of dxdx: dudx=4xdu=4xdx\frac{du}{dx} = 4x \quad \Rightarrow \quad du = 4x \, dx Thus, xdx=du4x \, dx = \frac{du}{4}.

Step 3: Change the limits of integration

When x=0x = 0: u=2(0)2+5=5u = 2(0)^2 + 5 = 5 When x=1x = 1: u=2(1)2+5=7u = 2(1)^2 + 5 = 7

Step 4: Substitute into the integral

Substituting uu and dudu into the integral: 01x2x2+5dx=57141udu\int_0^1 \frac{x}{2x^2 + 5} \, dx = \int_5^7 \frac{1}{4} \cdot \frac{1}{u} \, du

Step 5: Simplify and integrate

Now, we simplify the integral: 14571udu\frac{1}{4} \int_5^7 \frac{1}{u} \, du The integral of 1u\frac{1}{u} is lnu\ln|u|, so we have: 14[lnu]57=14(ln(7)ln(5))\frac{1}{4} \left[ \ln|u| \right]_5^7 = \frac{1}{4} \left( \ln(7) - \ln(5) \right)

Step 6: Final answer

Simplifying: 14ln(75)\frac{1}{4} \ln\left(\frac{7}{5}\right)

Thus, the value of the integral is: 14ln(75)\boxed{\frac{1}{4} \ln\left(\frac{7}{5}\right)}

Would you like more details on any part of this solution?

Related Questions:

  1. How do substitution methods work in integration?
  2. What happens if you use integration by parts instead of substitution here?
  3. How can you solve integrals involving rational functions?
  4. What are the properties of logarithmic functions that make them useful in integration?
  5. How would the solution change if the limits of integration were different?

Tip: Always check for substitutions that simplify complex expressions, especially in rational functions. This can make an otherwise difficult integral much more manageable.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Integration
Substitution Method
Logarithmic Functions

Formulas

∫ 1/u du = ln|u| + C
Substitution: u = 2x^2 + 5

Theorems

Fundamental Theorem of Calculus
Integration by Substitution

Suitable Grade Level

Grades 11-12