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Worked solution
Write down the integral
We integrate this rational function by first splitting it into partial fractions.
Factorise the denominator
The linear factors tell us the form of the partial fractions.
Set up the partial fraction form
Write one constant over each distinct linear factor.
Multiply through by the denominator
Clearing the fractions gives an identity valid for all x.
Substitute x=-2 to find A
This choice of x makes the other unknowns vanish (cover-up method).
Substitute x=1 to find B
This choice of x makes the other unknowns vanish (cover-up method).
Substitute x=4 to find C
This choice of x makes the other unknowns vanish (cover-up method).
Collect the constants
These constants complete the decomposition.
Write the partial fraction decomposition
Each simple fraction is now easy to integrate.
Split into standard integrals
Each term of the form k/(x-a) integrates to a logarithm.
Integrate the first term
Use \int \frac{k}{x-a}\,dx=k\ln|x-a|.
Integrate the second term
Use \int \frac{k}{x-a}\,dx=k\ln|x-a|.
Integrate the third term
Use \int \frac{k}{x-a}\,dx=k\ln|x-a|.
Combine the integrated terms
Add the logarithmic terms to form the antiderivative.
Select the correct option
The option matching the integrated decomposition is the correct answer.