What is the integral of (sec(x))/(1+sin(x)) ?

The integral of (sec(x))/(1+sin(x)) is 1/4 ln|1+sin(x)|-1/(2(1+sin(x)))-1/4 ln|sin(x)-1|+C

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

integral of (sec(x))/(1+sin(x))

\int \frac{sec ( x )}{1 + sin ( x )} d x

\frac{1}{4} ln ∣ 1 + sin (x) ∣ - \frac{1}{2 ( 1 + sin ( x ) )} - \frac{1}{4} ln ∣ sin (x) - 1 ∣ + C

Solution steps

\int \frac{sec ( x )}{1 + sin ( x )} d x

Apply Trigonometric Substitution

= \int \frac{1}{( 1 + u ) ( 1 - u ^{2} )} d u

Apply u-substitution

= \int \frac{1}{v ( - v ^{2} + 2 v )} d v

Factor

\frac{1}{v ( - v ^{2} + 2 v )}

= \int \frac{1}{- v ^{2} ( v - 2 )} d v

Take the constant out:

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

= - \int \frac{1}{v ^{2} ( v - 2 )} d v

Take the partial fraction of

\frac{1}{v ^{2} ( v - 2 )} : - \frac{1}{4 v} - \frac{1}{2 v ^{2}} + \frac{1}{4 ( v - 2 )}

= - \int - \frac{1}{4 v} - \frac{1}{2 v ^{2}} + \frac{1}{4 ( v - 2 )} d v

Apply the Sum Rule:

\int f (x) \pm g (x) d x = \int f (x) d x \pm \int g (x) d x

= - (- \int \frac{1}{4 v} d v - \int \frac{1}{2 v ^{2}} d v + \int \frac{1}{4 ( v - 2 )} d v)

\int \frac{1}{4 v} d v = \frac{1}{4} ln ∣ v ∣

\int \frac{1}{2 v ^{2}} d v = - \frac{1}{2 v}

\int \frac{1}{4 ( v - 2 )} d v = \frac{1}{4} ln ∣ v - 2 ∣

= - (- \frac{1}{4} ln ∣ v ∣ - (- \frac{1}{2 v}) + \frac{1}{4} ln ∣ v - 2 ∣)

Substitute back

= - (- \frac{1}{4} ln ∣ 1 + sin (x) ∣ - (- \frac{1}{2 ( 1 + sin ( x ) )}) + \frac{1}{4} ln ∣ 1 + sin (x) - 2 ∣)

Simplify

- (- \frac{1}{4} ln ∣ 1 + sin (x) ∣ - (- \frac{1}{2 ( 1 + sin ( x ) )}) + \frac{1}{4} ln ∣ 1 + sin (x) - 2 ∣) : \frac{1}{4} ln ∣ 1 + sin (x) ∣ - \frac{1}{2 ( 1 + sin ( x ) )} - \frac{1}{4} ln ∣ sin (x) - 1 ∣

= \frac{1}{4} ln ∣ 1 + sin (x) ∣ - \frac{1}{2 ( 1 + sin ( x ) )} - \frac{1}{4} ln ∣ sin (x) - 1 ∣

Add a constant to the solution

= \frac{1}{4} ln ∣ 1 + sin (x) ∣ - \frac{1}{2 ( 1 + sin ( x ) )} - \frac{1}{4} ln ∣ sin (x) - 1 ∣ + C

What is the integral of (sec(x))/(1+sin(x)) ?
The integral of (sec(x))/(1+sin(x)) is 1/4 ln|1+sin(x)|-1/(2(1+sin(x)))-1/4 ln|sin(x)-1|+C