Math Problem Statement

Evaluate the integral: \( \int \frac{x^2 + 2}{x^2 - 3} \, dx \)

Solution

The integral shown in your image is:

x2+2x23dx\int \frac{x^2 + 2}{x^2 - 3} \, dx

Let me solve it step-by-step:

Step 1: Simplify the fraction

The numerator x2+2x^2 + 2 has a degree equal to the denominator x23x^2 - 3. Therefore, we perform polynomial long division.

Divide x2+2x^2 + 2 by x23x^2 - 3:

  • The quotient is 11.
  • The remainder is (2+3)=5(2 + 3) = 5.

Thus, we can rewrite the integrand as: x2+2x23=1+5x23.\frac{x^2 + 2}{x^2 - 3} = 1 + \frac{5}{x^2 - 3}.

Step 2: Break the integral into parts

Split the integral: x2+2x23dx=1dx+5x23dx.\int \frac{x^2 + 2}{x^2 - 3} \, dx = \int 1 \, dx + \int \frac{5}{x^2 - 3} \, dx.

Step 3: Solve each part

  1. The first term: 1dx=x.\int 1 \, dx = x.

  2. The second term: For 5x23dx\int \frac{5}{x^2 - 3} \, dx, let a2=3a^2 = 3, so the denominator becomes (x2a2)(x^2 - a^2). Using the standard formula for this type of integral: 1x2a2dx=12alnxax+a+C,\int \frac{1}{x^2 - a^2} \, dx = \frac{1}{2a} \ln \left| \frac{x - a}{x + a} \right| + C, we compute: 5x23dx=523lnx3x+3.\int \frac{5}{x^2 - 3} \, dx = \frac{5}{2\sqrt{3}} \ln \left| \frac{x - \sqrt{3}}{x + \sqrt{3}} \right|.

Step 4: Combine the results

The final solution is: x2+2x23dx=x+523lnx3x+3+C.\int \frac{x^2 + 2}{x^2 - 3} \, dx = x + \frac{5}{2\sqrt{3}} \ln \left| \frac{x - \sqrt{3}}{x + \sqrt{3}} \right| + C.

Would you like a more detailed breakdown of any step?


Related Questions:

  1. How do you perform polynomial long division for integrals?
  2. Why do we rewrite x2+2x23\frac{x^2 + 2}{x^2 - 3} as 1+5x231 + \frac{5}{x^2 - 3}?
  3. What is the derivation of the integral formula for 1x2a2dx\int \frac{1}{x^2 - a^2} \, dx?
  4. How does the constant of integration CC affect the result?
  5. Can this method be extended to higher-degree polynomials?

Tip:

Always check if the numerator's degree is greater than or equal to the denominator's degree before integrating rational functions. This helps decide if polynomial long division is required.

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Math Problem Analysis

Mathematical Concepts

Integration
Rational Functions
Polynomial Long Division
Logarithmic Integration

Formulas

\( \int \frac{1}{x^2 - a^2} \, dx = \frac{1}{2a} \ln \left| \frac{x - a}{x + a} \right| + C \)
Polynomial Long Division

Theorems

Integration of Rational Functions

Suitable Grade Level

Undergraduate (Calculus I/II)