/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 68 Find the indefinite integral. ... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Find the indefinite integral. $$ \int \frac{1}{(x+1) \sqrt{(x+1)^{2}-9}} d x $$

Short Answer

Expert verified
The short answer is: \(\int \frac{1}{(x+1) \sqrt{(x+1)^{2}-9}} d x = \text{arcsech} \frac{x+1}{3} + C\).

Step by step solution

01

Make a substitution

In order to simplify the given integral, use the following substitution: $$ u = x + 1 $$ Then, $$ d u = d x $$ The integral can now be rewritten as: $$ \int \frac{1}{u \sqrt{u^2 - 9}} d u $$
02

Recognize the expression as an inverse trigonometric function

Notice that the expression inside the integral is now in the form $$ \frac{1}{u \sqrt{u^2 - a^2}} $$ where \(a = 3\). This form corresponds to the derivative of the inverse hyperbolic secant function (\(\text{arcsech}\)), given by $$ \frac{d}{d u} \text{arcsech} \frac{u}{a} = \frac{1}{u \sqrt{u^2 - a^2}} $$
03

Integrate

Now that we've recognized the expression in the integral as the derivative of the inverse hyperbolic secant function, we can integrate: $$ \int \frac{1}{u \sqrt{u^2 - 9}} d u = \text{arcsech} \frac{u}{3} + C $$ where \(C\) is the constant of integration.
04

Replace the original variable

Finally, replace \(u\) with \(x + 1\): $$ \text{arcsech} \frac{u}{3} + C = \text{arcsech} \frac{x+1}{3} + C $$
05

Write down the final answer

The indefinite integral of the given function is: $$ \int \frac{1}{(x+1) \sqrt{(x+1)^{2}-9}} d x = \text{arcsech} \frac{x+1}{3} + C $$

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Integration Techniques
Understanding various integration techniques is crucial for solving complex integrals in calculus. These methods include substitution, integration by parts, partial fractions, and trigonometric substitution, among others. Each method serves to simplify the integral into a form that can be easily evaluated.

In the given exercise, we use the substitution technique, which involves changing the variable of integration to reframe the integral into a more manageable form. In particular, we set a new variable, u, equal to x + 1, simplifying the algebraic structure of the integrand. This tactic often streamlines the integration process, making it easier to recognize and apply further integration rules or identify standard integral forms.
Inverse Hyperbolic Functions
Inverse hyperbolic functions, such as arcsech, are reciprocal functions of hyperbolic functions and have useful derivatives that frequently appear in calculus. Recognizing these derivatives within integrals allows us to apply the antiderivative directly, bypassing complicated integration steps.

As we noted in the step-by-step solution, the integrand matches the derivative of the inverse hyperbolic secant function when a = 3. This is crucial because it allows us to express the original integral in terms of familiar, elementary functions and ultimately find a closed-form solution. Sufficient familiarity with these functions can significantly expedite the integration process in problems involving hyperbolic expressions.
Trigonometric Substitution
While not directly used in this problem, trigonometric substitution is another powerful integration technique that is particularly useful for integrals involving square roots of quadratic expressions. It involves substituting the variable with a trigonometric function that simplifies the integrand's algebraic form, often leveraging the Pythagorean identity.

Even though the initial integral resembled an expression that might require trigonometric substitution, our specific exercise was more straightforwardly managed by recognizing the relationship to inverse hyperbolic functions. However, understanding trigonometric substitution remains valuable because it is widely applicable in a range of situations, including ones where inverse trigonometric or hyperbolic functions are not immediately recognizable.
Integral Calculus
Integral calculus is a branch of calculus focused on finding and applying integrals, which represent the accumulation of quantities and the areas under curves. It is the inverse operation of differentiation and is essential in determining antiderivatives, solving area and volume problems, and in physics, finding quantities like displacement, work, and total charge.

In the provided indefinite integral example, we use integral calculus to find the antiderivative of a function with respect to x. Here, no limits of integration are specified, hence the 'indefinite' in indefinite integral. What remains constant in integral calculus, as demonstrated in the exercise, is the addition of the constant of integration, C, which accounts for the general solution to the antiderivative.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

According to data from the American Petroleum Institute, the U.S. Strategic Petroleum Reserves from the beginning of 1981 to the beginning of 1990 can be approximated by the function $$ S(t)=\frac{613.7 t^{2}+1449.1}{t^{2}+6.3} \quad 0 \leq t \leq 9$$ where \(S(t)\) is measured in millions of barrels and \(t\) in years, with \(t=0\) corresponding to the beginning of 1981 . Using the Trapezoidal Rule with \(n=9\), estimate the average petroleum reserves from the beginning of 1981 to the beginning of 1990 .

Evaluate the integral. $$ \int_{0}^{1} \frac{e^{2 x}}{1+e^{4 x}} d x $$

The concentration of a drug in an organ at any time \(t\), in seconds) is given by $$C(t)=\left\\{\begin{array}{ll} 0.3 t-18\left(1-e^{-t / 60}\right) & \text { if } 0 \leq t \leq 20 \\ 18 e^{-t / 60}-12 e^{-(t-20) / 60} & \text { if } t>20 \end{array}\right.$$ where \(C(t)\) is measured in grams per cubic centimeter \(\left(\mathrm{g} / \mathrm{cm}^{3}\right)\). Find the average concentration of the drug in the organ over the first 30 sec after it is administered.

The number of hours of daylight at any time \(t\) in Chicago is approximated by $$L(t)=2.8 \sin \left[\frac{2 \pi}{365}(t-79)\right]+12$$ where \(t\) is measured in days and \(t=0\) corresponds to January 1 . What is the daily average number of hours of daylight in Chicago over the year? Over the summer months from June \(21(t=171)\) through September \(20(t=262)\) ?

Find the area of the region under the graph off on \([a, b]\). $$ f(x)=\sec ^{2} x ; \quad\left[0, \frac{\pi}{4}\right] $$

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.