Questions: Express the integrand as a sum of partial fractions and evaluate the integral.
[
int fracd x4-9 x^2
]
Transcript text: Express the integrand as a sum of partial fractions and evaluate the integral.
\[
\int \frac{d x}{4-9 x^{2}}
\]
Solution
Solution Steps
Step 1: Factor the Denominator
We start with the integral
\[
\int \frac{d x}{4 - 9 x^{2}}.
\]
The denominator can be factored as
\[
4 - 9 x^{2} = (2 - 3x)(2 + 3x).
\]
Step 2: Partial Fraction Decomposition
Next, we express the integrand as a sum of partial fractions:
\[
\frac{1}{4 - 9 x^{2}} = \frac{1}{4(3x + 2)} - \frac{1}{4(3x - 2)}.
\]
Step 3: Integrate Each Term
We then integrate each term separately:
\[
\int \left( \frac{1}{4(3x + 2)} - \frac{1}{4(3x - 2)} \right) d x.
\]
This results in:
\[
-\frac{1}{12} \log |3x - 2| + \frac{1}{12} \log |3x + 2| + C,
\]
where \(C\) is the constant of integration.