What is the integral of 1/(xsqrt(2+9x^2)) ?

The integral of 1/(xsqrt(2+9x^2)) is 1/(sqrt(2))ln|tan((arctan(3/(sqrt(2))x))/2)|+C

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integral of 1/(xsqrt(2+9x^2))

\int \frac{1}{x 2 + 9 x ^{2}} d x

\frac{1}{2} ln tan \frac{arctan ( \frac{3}{2} x )}{2} + C

Solution steps

\int \frac{1}{x 2 + 9 x ^{2}} d x

Apply Trigonometric Substitution

= \int \frac{sec ( u )}{2 tan ( u )} d u

Take the constant out:

\int a \cdot f (x) d x = a \cdot \int f (x) d x

= \frac{1}{2} \cdot \int \frac{sec ( u )}{tan ( u )} d u

Apply u-substitution

= \frac{1}{2} \cdot \int \frac{1}{v} d v

Use the common integral:

\int \frac{1}{v} d v = ln (∣ v ∣)

= \frac{1}{2} ln ∣ v ∣

Substitute back

= \frac{1}{2} ln tan \frac{arctan ( \frac{3}{2} x )}{2}

Add a constant to the solution

= \frac{1}{2} ln tan \frac{arctan ( \frac{3}{2} x )}{2} + C

What is the integral of 1/(xsqrt(2+9x^2)) ?
The integral of 1/(xsqrt(2+9x^2)) is 1/(sqrt(2))ln|tan((arctan(3/(sqrt(2))x))/2)|+C