Study.com

We're sorry, this computer has been flagged for suspicious activity.

If you are a member, we ask that you confirm your identity by entering in your email.

You will then be sent a link via email to verify your account.

If you are not a member or are having any other problems, please contact customer support.

Thank you for your cooperation

Radical Equation Word Problems - Examples & Practice - Expii

Logo for British Columbia/Yukon Open Authoring Platform

Want to create or adapt OER like this? Learn how BCcampus supports open education and how you can access Pressbooks . Learn more about how Pressbooks supports open publishing practices. -->

Roots and Radicals

Solve Radical Equations

Learning Objectives

By the end of this section, you will be able to:

Before you get started, take this readiness quiz.

{\left(y-3\right)}^{2}.

In this section we will solve equations that have a variable in the radicand of a radical expression. An equation of this type is called a radical equation .

An equation in which a variable is in the radicand of a radical expression is called a radical equation .

As usual, when solving these equations, what we do to one side of an equation we must do to the other side as well. Once we isolate the radical, our strategy will be to raise both sides of the equation to the power of the index. This will eliminate the radical.

Solving radical equations containing an even index by raising both sides to the power of the index may introduce an algebraic solution that would not be a solution to the original radical equation. Again, we call this an extraneous solution as we did when we solved rational equations.

In the next example, we will see how to solve a radical equation. Our strategy is based on raising a radical with index n to the n th power. This will eliminate the radical.

\text{For}\phantom{\rule{0.2em}{0ex}}a\ge 0,\phantom{\rule{0.2em}{0ex}}{\left(\sqrt[n]{a}\right)}^{n}=a.

When we use a radical sign, it indicates the principal or positive root. If an equation has a radical with an even index equal to a negative number, that equation will have no solution.

\sqrt{9k-2}+1=0.

Because the square root is equal to a negative number, the equation has no solution.

\sqrt{2r-3}+5=0.

If one side of an equation with a square root is a binomial, we use the Product of Binomial Squares Pattern when we square it.

\begin{array}{}\\ \\ {\left(a+b\right)}^{2}={a}^{2}+2ab+{b}^{2}\\ {\left(a-b\right)}^{2}={a}^{2}-2ab+{b}^{2}\end{array}

Don’t forget the middle term!

\sqrt{p-1}+1=p.

When the index of the radical is 3, we cube both sides to remove the radical.

{\left(\sqrt[3]{a}\right)}^{3}=a

Sometimes the solution of a radical equation results in two algebraic solutions, but one of them may be an extraneous solution !

\sqrt{r+4}-r+2=0.

When there is a coefficient in front of the radical, we must raise it to the power of the index, too.

\text{3}\phantom{\rule{0.2em}{0ex}}\sqrt{3x-5}-8=4.

Solve Radical Equations with Two Radicals

If the radical equation has two radicals, we start out by isolating one of them. It often works out easiest to isolate the more complicated radical first.

In the next example, when one radical is isolated, the second radical is also isolated.

\sqrt[3]{4x-3}=\sqrt[3]{3x+2}.

Sometimes after raising both sides of an equation to a power, we still have a variable inside a radical. When that happens, we repeat Step 1 and Step 2 of our procedure. We isolate the radical and raise both sides of the equation to the power of the index again.

\sqrt{m}+1=\sqrt{m+9}.

We summarize the steps here. We have adjusted our previous steps to include more than one radical in the equation This procedure will now work for any radical equations.

If yes, repeat Step 1 and Step 2 again.

{\left(a+b\right)}^{2}={a}^{2}+2ab+{b}^{2}

Use Radicals in Applications

As you progress through your college courses, you’ll encounter formulas that include radicals in many disciplines. We will modify our Problem Solving Strategy for Geometry Applications slightly to give us a plan for solving applications with formulas from any discipline.

One application of radicals has to do with the effect of gravity on falling objects. The formula allows us to determine how long it will take a fallen object to hit the gound.

On Earth, if an object is dropped from a height of h feet, the time in seconds it will take to reach the ground is found by using the formula

t=\frac{\sqrt{h}}{4}.

It would take 2 seconds for an object dropped from a height of 64 feet to reach the ground.

t=\frac{\sqrt{h}}{4}

Police officers investigating car accidents measure the length of the skid marks on the pavement. Then they use square roots to determine the speed , in miles per hour, a car was going before applying the brakes.

If the length of the skid marks is d feet, then the speed, s , of the car before the brakes were applied can be found by using the formula

s=\sqrt{24d}

Access these online resources for additional instruction and practice with solving radical equations.

Key Concepts

\begin{array}{c}{\left(a+b\right)}^{2}={a}^{2}+2ab+{b}^{2}\\ {\left(a-b\right)}^{2}={a}^{2}-2ab+{b}^{2}\end{array}

Practice Makes Perfect

In the following exercises, solve.

\sqrt{5x-6}=8

no solution

\sqrt{3y-4}=-2

In the following exercises, solve. Round approximations to one decimal place.

s=\sqrt{A}

Writing Exercises

\sqrt{x}+1=0

Answers will vary.

ⓐ After completing the exercises, use this checklist to evaluate your mastery of the objectives of this section.

The table has 4 columns and 4 rows. The first row is a header row with the headers “I can…”, “Confidently”, “With some help.”, and “No – I don’t get it!”. The first column contains the phrases “Solve radical equations”, “solve radical equations with two radicals”, and “use radicals in applications”. The other columns are left blank so the learner can indicate their level of understanding.

ⓑ After reviewing this checklist, what will you do to become confident for all objectives?

Intermediate Algebra by OSCRiceUniversity is licensed under a Creative Commons Attribution 4.0 International License , except where otherwise noted.

Share This Book

IMAGES

  1. Radical Equation Word Problems

    word problem involving radical equations basic

  2. Solving Radical Equations Worksheets

    word problem involving radical equations basic

  3. How to Solve Advanced Word Problems Involving Radical Equations

    word problem involving radical equations basic

  4. Solving Radical Equations Word Problems Worksheet

    word problem involving radical equations basic

  5. Word Problems Involving Radical Equations With Solutions

    word problem involving radical equations basic

  6. How to Solve Basic Word Problems Involving Radical Equations

    word problem involving radical equations basic

VIDEO

  1. Section 2.4: More Radical Equations

  2. Algebra Solving Radical Equations

  3. ALGEBRA: Solving Radical Equations

  4. 5.4 Solving Radical Equations Day 1

  5. 11.10 Solve Radical Equations Part 1

  6. Solving Radical Equations (Part one)

COMMENTS

  1. 03 11 Word problem involving radical equations: Basic

    03 11 Word problem involving radical equations: Basic. 5.2K views 8 years ago Module 3 · Math by Caroline. Math by Caroline. 247 subscribers.

  2. Word Problems Involving Radical Equations

    This video is about how to solve word problems involving radical equations. I hope this video will help you! Please support this channel by

  3. How to Solve Basic Word Problems Involving Radical Equations

    Solving a Basic Word Problem Involving Radical Equations: Unknown Inside the Radical Example ... Find the length, L, of the pendulum if 2π 2 π is the period. Step

  4. How to Solve Advanced Word Problems Involving Radical Equations

    Steps for Solving an Advanced Word Problem Involving Radical Equations ... Step 1. Read the problem carefully and draw an illustration, if possible. Step 2.

  5. Radical Equation Word Problems

    Radical Equations Word Problems. Taylor is a famous sculptor, and she wants to build. Image source: By Caroline Kulczycky. Report. Share. 2. Like.

  6. Solving Radical Equations 10.3

    Essential Question How can you solve an equation that ... Solving a Square Root Equation ... Solve real-life problems involving radical equations. Solving

  7. Applied Use of Radical Equations

    Directions: Solve the following problems dealing with radical equations. Show your work algebraically. Remember that you can use your graphing calculator to

  8. Solve Radical Equations

    Solve Radical Equations · Isolate the radical on one side of the equation. · Raise both sides of the equation to the power of the index. · Solve the new equation.

  9. Solving World problem involving Radical Equations.

    if a person's eye is x meters above sea level, and she can see y meter in the horizon, then y= square root 3.75 square root x. what if the eye level is 5.29

  10. Applications Using Radicals

    Solving Problems Involving Radical Expressions - Example 1. basic. Solving Word Problems Involving Basic Radical Properties and Operations.