Math Problem Statement

∫ (2x^2 + 7x - 3) / (x - 2) dx

Solution

The given expression is:

2x2+7x3x2dx\int \frac{2x^2 + 7x - 3}{x - 2} \, dx

Solution Approach:

We will solve this by performing polynomial long division on 2x2+7x3x2\frac{2x^2 + 7x - 3}{x - 2}, since the degree of the numerator is higher than that of the denominator.

Step 1: Perform polynomial long division

We divide 2x2+7x32x^2 + 7x - 3 by x2x - 2.

  • Divide the leading terms: 2x2x=2x\frac{2x^2}{x} = 2x.

  • Multiply 2x2x by x2x - 2, which gives 2x24x2x^2 - 4x.

  • Subtract (2x24x)(2x^2 - 4x) from (2x2+7x3)(2x^2 + 7x - 3) to get:

    (2x2+7x3)(2x24x)=11x3(2x^2 + 7x - 3) - (2x^2 - 4x) = 11x - 3

  • Now, divide 11x11x by xx, which gives 1111.

  • Multiply 1111 by x2x - 2, which gives 11x2211x - 22.

  • Subtract (11x22)(11x - 22) from (11x3)(11x - 3) to get:

    (11x3)(11x22)=19(11x - 3) - (11x - 22) = 19

So, the result of the division is:

2x+11+19x22x + 11 + \frac{19}{x - 2}

Step 2: Integrate the result

Now, the integral becomes:

(2x+11+19x2)dx\int \left(2x + 11 + \frac{19}{x - 2}\right) dx

We can integrate this term by term:

  • 2xdx=x2\int 2x \, dx = x^2
  • 11dx=11x\int 11 \, dx = 11x
  • 19x2dx=19lnx2\int \frac{19}{x - 2} \, dx = 19 \ln|x - 2|

Thus, the solution to the integral is:

x2+11x+19lnx2+Cx^2 + 11x + 19 \ln|x - 2| + C

where CC is the constant of integration.

Final Answer:

x2+11x+19lnx2+C\boxed{x^2 + 11x + 19 \ln|x - 2| + C}

Let me know if you need further clarification or additional details!

Here are 5 related questions for further exploration:

  1. How would the solution change if the denominator was x+2x + 2 instead of x2x - 2?
  2. How would you integrate x2+7x3x1\frac{x^2 + 7x - 3}{x - 1}?
  3. What happens if the numerator and denominator are both cubic polynomials?
  4. How would you integrate a rational function where the numerator is of a lower degree than the denominator?
  5. How does the natural logarithm lnx2\ln|x - 2| appear in this integration?

Tip: Polynomial long division is essential when the degree of the numerator exceeds the degree of the denominator in a rational function.

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Math Problem Analysis

Mathematical Concepts

Polynomial Division
Integration
Natural Logarithms

Formulas

∫ (f(x) / g(x)) dx where f(x) and g(x) are polynomials
∫ ln(x) dx = x ln|x| - x
Polynomial long division

Theorems

Fundamental Theorem of Calculus
Polynomial Long Division

Suitable Grade Level

Grades 11-12 (Advanced High School Calculus)