Skip to main content
Ch. 8 - Techniques of Integration
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077Not the one you use?Change textbook
Chapter 8, Problem 8.8.32

The integrals in Exercises 1–34 converge. Evaluate the integrals without using tables.
∫₀² dx / √|x − 1|

Verified step by step guidance
1
First, recognize that the integral involves the expression \(\sqrt{|x - 1|}\), which has an absolute value inside the square root. This means the behavior of the integrand changes at \(x = 1\), so we should split the integral at this point.
Rewrite the integral as the sum of two integrals: \(\int_0^1 \frac{dx}{\sqrt{1 - x}} + \int_1^2 \frac{dx}{\sqrt{x - 1}}\). Notice how the absolute value affects the expression inside the square root on each interval.
For the first integral, \(\int_0^1 \frac{dx}{\sqrt{1 - x}}\), use the substitution \(u = 1 - x\), which implies \(du = -dx\). Adjust the limits accordingly and rewrite the integral in terms of \(u\).
For the second integral, \(\int_1^2 \frac{dx}{\sqrt{x - 1}}\), use the substitution \(v = x - 1\), which implies \(dv = dx\). Adjust the limits accordingly and rewrite the integral in terms of \(v\).
Evaluate both integrals using the power rule for integrals: \(\int u^{n} du = \frac{u^{n+1}}{n+1} + C\) for \(n \neq -1\). After evaluating, sum the results to get the value of the original integral.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
7m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Improper Integrals

Improper integrals involve integrands with infinite discontinuities or infinite limits of integration. In this problem, the integrand has a singularity at x = 1, where the denominator becomes zero, requiring careful evaluation of the integral as a limit approaching the point of discontinuity.
Recommended video:
11:11
Improper Integrals: Infinite Intervals

Absolute Value and Piecewise Functions

The absolute value inside the square root splits the integral into separate intervals where the expression inside changes sign. Understanding how to rewrite |x - 1| as (1 - x) or (x - 1) depending on the interval is essential to correctly set up and evaluate the integral.
Recommended video:
05:36
Piecewise Functions

Integration Techniques for Power Functions

Integrating functions of the form 1/√(x - a) involves recognizing them as power functions with fractional exponents. Applying the power rule for integration, ∫x^n dx = x^(n+1)/(n+1), is necessary after rewriting the integrand appropriately to find the antiderivative.
Recommended video:
07:32
Representing Functions as Power Series