Primitive of Reciprocal of a x + b/Examples/x - a

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Example of Use of Primitive of $\dfrac 1 {a x + b}$

$\ds \int \frac {\d x} {x - a} = \ln \size {x - a} + C$


Proof

\(\ds \int \frac {\d x} {a x + b}\) \(=\) \(\ds \frac 1 a \ln \size {a x + b} + C\) Primitive of $\dfrac 1 {a x + b}$
\(\ds \) \(=\) \(\ds \ln \size {x - a} + C\) substituting $a \gets 1$, $b \gets -a$

$\blacksquare$


Sources