LIAL HORNSBY SCHNEIDER

Slides:



Advertisements
Similar presentations
Numbers Treasure Hunt Following each question, click on the answer. If correct, the next page will load with a graphic first – these can be used to check.
Advertisements

5.1 Rules for Exponents Review of Bases and Exponents Zero Exponents
Angstrom Care 培苗社 Quadratic Equation II
AP STUDY SESSION 2.
1
Copyright © 2003 Pearson Education, Inc. Slide 1 Computer Systems Organization & Architecture Chapters 8-12 John D. Carpinelli.
Copyright © 2011, Elsevier Inc. All rights reserved. Chapter 6 Author: Julia Richards and R. Scott Hawley.
Properties Use, share, or modify this drill on mathematic properties. There is too much material for a single class, so you’ll have to select for your.
Complex Numbers and Roots
Properties of Real Numbers CommutativeAssociativeDistributive Identity + × Inverse + ×
1 Click here to End Presentation Software: Installation and Updates Internet Download CD release NACIS Updates.
Solve Multi-step Equations
Break Time Remaining 10:00.
Factoring Polynomials
Factoring Quadratics — ax² + bx + c Topic
PP Test Review Sections 6-1 to 6-6
Digital Lessons on Factoring
PRECALCULUS I Complex Numbers
Slide 6-1 COMPLEX NUMBERS AND POLAR COORDINATES 8.1 Complex Numbers 8.2 Trigonometric Form for Complex Numbers Chapter 8.
Copyright © 2013, 2009, 2005 Pearson Education, Inc.
Simplify each expression.
Complex Numbers Objectives:
Warm-up: Solve the equation. Answers.
MAT 205 F08 Chapter 12 Complex Numbers.
4.6 Perform Operations with Complex Numbers
Bellwork Do the following problem on a ½ sheet of paper and turn in.
Columbus State Community College
Exarte Bezoek aan de Mediacampus Bachelor in de grafische en digitale media April 2014.
Solving Quadratic Equations Solving Quadratic Equations
Copyright © 2013, 2009, 2006 Pearson Education, Inc. 1 Section 5.5 Dividing Polynomials Copyright © 2013, 2009, 2006 Pearson Education, Inc. 1.
Copyright © 2012, Elsevier Inc. All rights Reserved. 1 Chapter 7 Modeling Structure with Blocks.
1 RA III - Regional Training Seminar on CLIMAT&CLIMAT TEMP Reporting Buenos Aires, Argentina, 25 – 27 October 2006 Status of observing programmes in RA.
Functions, Graphs, and Limits
Basel-ICU-Journal Challenge18/20/ Basel-ICU-Journal Challenge8/20/2014.
Chapter 1: Expressions, Equations, & Inequalities
1..
Adding Up In Chunks.
1 10 pt 15 pt 20 pt 25 pt 5 pt 10 pt 15 pt 20 pt 25 pt 5 pt 10 pt 15 pt 20 pt 25 pt 5 pt 10 pt 15 pt 20 pt 25 pt 5 pt 10 pt 15 pt 20 pt 25 pt 5 pt Synthetic.
Rational and Irrational Numbers
4.5 Solve Quadratic Equations by Finding Square Roots
Slide R - 1 Copyright © 2009 Pearson Education, Inc. Publishing as Pearson Prentice Hall Active Learning Lecture Slides For use with Classroom Response.
9-8 Completing the Square Warm Up Lesson Presentation Lesson Quiz
U1A L1 Examples FACTORING REVIEW EXAMPLES.
11.2 Solving Quadratic Equations by Completing the Square
1 hi at no doifpi me be go we of at be do go hi if me no of pi we Inorder Traversal Inorder traversal. n Visit the left subtree. n Visit the node. n Visit.
Copyright © 2010 Pearson Education, Inc. All rights reserved Sec
Essential Cell Biology
12 System of Linear Equations Case Study
Exponents and Radicals
Clock will move after 1 minute
PSSA Preparation.
Immunobiology: The Immune System in Health & Disease Sixth Edition
Physics for Scientists & Engineers, 3rd Edition
Energy Generation in Mitochondria and Chlorplasts
Copyright © Cengage Learning. All rights reserved.
4.7 Complete the Square.
Completing the Square Topic
1 Decidability continued…. 2 Theorem: For a recursively enumerable language it is undecidable to determine whether is finite Proof: We will reduce the.
Copyright © Cengage Learning. All rights reserved.
1 Equations and Inequalities Sections 1.1–1.4
Chapter 1.4 Quadratic Equations.
Graph quadratic equations. Complete the square to graph quadratic equations. Use the Vertex Formula to graph quadratic equations. Solve a Quadratic Equation.
Solving Quadratic Equations Section 1.3
Copyright © 2013, 2009, 2005 Pearson Education, Inc. 1 1 Equations and Inequalities Copyright © 2013, 2009, 2005 Pearson Education, Inc.
Chapter P Prerequisites: Fundamental Concepts of Algebra 1 Copyright © 2014, 2010, 2007 Pearson Education, Inc. 1 P.7 Equations.
10 Quadratic Equations.
Copyright © 2017, 2013, 2009 Pearson Education, Inc.
4.5: Completing the square
Section 9.1 “Properties of Radicals”
Presentation transcript:

LIAL HORNSBY SCHNEIDER COLLEGE ALGEBRA LIAL HORNSBY SCHNEIDER

1.4 Quadratic Equations Solving a Quadratic Equation Completing the Square The Quadratic Formula Solving for a Specified Variable The Discriminant

Quadratic Equation in One Variable An equation that can be written in the form where a, b, and c are real numbers with a ≠ 0, is a quadratic equation. The given form is called standard form.

Second-degree Equation A quadratic equation is a second-degree equation. This is an equation with a squared variable term and no terms of greater degree.

Zero-Factor Property If a and b are complex numbers with ab = 0, then a = 0 or b = 0 or both.

Solve Solution: USING THE ZERO-FACTOR PROPERTY Example 1 Standard form

Solve Solution: USING THE ZERO-FACTOR PROPERTY Example 1 Solve each equation.

Square-Root Property A quadratic equation of the form x2 = k can also be solved by factoring Subtract k. Factor. Zero-factor property. Solve each equation.

Square Root Property If x2 = k, then

Square-Root Property That is, the solution of Both solutions are real if k > 0, and both are imaginary if k < 0 If k = 0, then this is sometimes called a double solution. If k < 0, we write the solution set as

Solve each quadratic equation. a. USING THE SQUARE ROOT PROPERTY Example 2 Solve each quadratic equation. a. Solution: By the square root property, the solution set is

Solve each quadratic equation. b. USING THE SQUARE ROOT PROPERTY Example 2 Solve each quadratic equation. b. Solution: Since the solution set of x2 = − 25 is

Solve each quadratic equation. c. USING THE SQUARE ROOT PROPERTY Example 2 Solve each quadratic equation. c. Solution: Use a generalization of the square root property. Generalized square root property. Add 4.

Solving A Quadratic Equation By Completing The Square To solve ax2 + bx + c = 0, by completing the square: Step 1 If a ≠ 1, divide both sides of the equation by a. Step 2 Rewrite the equation so that the constant term is alone on one side of the equality symbol. Step 3 Square half the coefficient of x, and add this square to both sides of the equation. Step 4 Factor the resulting trinomial as a perfect square and combine like terms on the other side. Step 5 Use the square root property to complete the solution.

Solve x2 – 4x –14 = 0 by completing the square. USING THE METHOD OF COMPLETING THE SQUARE a = 1 Example 3 Solve x2 – 4x –14 = 0 by completing the square. Solution Step 1 This step is not necessary since a = 1. Step 2 Add 14 to both sides. Step 3 add 4 to both sides. Step 4 Factor; combine terms.

Solve x2 – 4x –14 = 0 by completing the square. USING THE METHOD OF COMPLETING THE SQUARE a = 1 Example 3 Solve x2 – 4x –14 = 0 by completing the square. Solution Step 4 Factor; combine terms. Step 5 Square root property. Take both roots. Add 2. Simplify the radical. The solution set is

Solve 9x2 – 12x + 9 = 0 by completing the square. USING THE METHOD OF COMPLETING THE SQUARE a ≠ 1 Example 4 Solve 9x2 – 12x + 9 = 0 by completing the square. Solution Divide by 9. (Step 1) Add – 1. (Step 2)

Solve 9x2 – 12x + 9 = 0 by completing the square. USING THE METHOD OF COMPLETING THE SQUARE a = 1 Example 4 Solve 9x2 – 12x + 9 = 0 by completing the square. Solution Factor, combine terms. (Step 4) Square root property

Solve 9x2 – 12x + 9 = 0 by completing the square. USING THE METHOD OF COMPLETING THE SQUARE a = 1 Example 4 Solve 9x2 – 12x + 9 = 0 by completing the square. Solution Square root property Quotient rule for radicals Add ⅔.

Solve 9x2 – 12x + 9 = 0 by completing the square. USING THE METHOD OF COMPLETING THE SQUARE a = 1 Example 4 Solve 9x2 – 12x + 9 = 0 by completing the square. Solution Add ⅔. The solution set is

The Quadratic Formula The method of completing the square can be used to solve any quadratic equation. If we start with the general quadratic equation, ax2 + bx + c = 0, a ≠ 0, and complete the square to solve this equation for x in terms of the constants a, b, and c, the result is a general formula for solving any quadratic equation. We assume that a > 0.

Quadratic Formula The solutions of the quadratic equation ax2 + bx + c = 0, where a ≠ 0, are

Caution Notice that the fraction bar in the quadratic formula extends under the – b term in the numerator.

Solve x2 – 4x = – 2 Solution: Here a = 1, b = – 4, c = 2 USING THE QUADRATIC FORMULA (REAL SOLUTIONS) Example 5 Solve x2 – 4x = – 2 Solution: Write in standard form. Here a = 1, b = – 4, c = 2 Quadratic formula.

The fraction bar extends under – b. USING THE QUADRATIC FORMULA (REAL SOLUTIONS) Example 5 Solve x2 – 4x = – 2 Solution: Quadratic formula. The fraction bar extends under – b.

The fraction bar extends under – b. USING THE QUADRATIC FORMULA (REAL SOLUTIONS) Example 5 Solve x2 – 4x = – 2 Solution: The fraction bar extends under – b.

Factor first, then divide. USING THE QUADRATIC FORMULA (REAL SOLUTIONS) Example 5 Solve x2 – 4x = – 2 Solution: Factor out 2 in the numerator. Factor first, then divide. Lowest terms. The solution set is

Use parentheses and substitute carefully to avoid errors. USING THE QUADRATIC FORMULA (NONREAL COMPLEX SOLUTIONS) Example 6 Solve 2x2 = x – 4. Solution: Write in standard form. Quadratic formula; a = 2, b = – 1, c = 4 Use parentheses and substitute carefully to avoid errors.

Solve 2x2 = x – 4. Solution: The solution set is Example 6 USING THE QUADRATIC FORMULA (NONREAL COMPLEX SOLUTIONS) Example 6 Solve 2x2 = x – 4. Solution: The solution set is

Cubic Equation The equation x3 + 8 = 0 that follows is called a cubic equation because of the degree 3 term. Some higher-degree equations can be solved using factoring and the quadratic formula.

Solve Solution or or SOLVING A CUBIC EQUATION Example 7 Factor as a sum of cubes. or Zero-factor property or Quadratic formula; a = 1, b = – 2, c = 4

Solve Solution SOLVING A CUBIC EQUATION Example 7 Simplify. Simplify the radical. Factor out 2 in the numerator.

SOLVING A CUBIC EQUATION Example 7 Solve Solution Lowest terms

Goal: Isolate d, the specified variable. SOLVING FOR A QUADRATIC VARIABLE IN A FORMULA Example 8 Solve for the specified variable. Use  when taking square roots. a. Solution Goal: Isolate d, the specified variable. Multiply by 4. Divide by .

See the Note following this example. SOLVING FOR A QUADRATIC VARIABLE IN A FORMULA Example 8 Solve the specified variable. Use  when taking square roots. a. Solution Divide by . Square root property See the Note following this example.

Solve the specified variable. Use  when taking square roots. SOLVING FOR A QUADRATIC VARIABLE IN A FORMULA Example 8 Solve the specified variable. Use  when taking square roots. a. Solution Square root property Rationalize the denominator.

Solve the specified variable. Use  when taking square roots. SOLVING FOR A QUADRATIC VARIABLE IN A FORMULA Example 8 Solve the specified variable. Use  when taking square roots. a. Solution Rationalize the denominator. Multiply numerators; multiply denominators.

Solve the specified variable. Use  when taking square roots. SOLVING FOR A QUADRATIC VARIABLE IN A FORMULA Example 8 Solve the specified variable. Use  when taking square roots. a. Solution Multiply numerators; multiply denominators. Simplify.

Solving for a Specified Variable Note In Example 8, we took both positive and negative square roots. However, if the variable represents a distance or length in an application, we would consider only the positive square root.

Solve the specified variable. Use  when taking square roots. SOLVING FOR A QUADRATIC VARIABLE IN A FORMULA Example 8 Solve the specified variable. Use  when taking square roots. b. Solution Write in standard form. Now use the quadratic formula to find t.

Solve the specified variable. Use  when taking square roots. SOLVING FOR A QUADRATIC VARIABLE IN A FORMULA Example 8 Solve the specified variable. Use  when taking square roots. b. Solution a = r, b = – s, and c = – k

Solve the specified variable. Use  when taking square roots. SOLVING FOR A QUADRATIC VARIABLE IN A FORMULA Example 8 Solve the specified variable. Use  when taking square roots. b. Solution a = r, b = – s, and c = – k Simplify.

The Discriminant The Discriminant The quantity under the radical in the quadratic formula, b2 – 4ac, is called the discriminant. Discriminant

The Discriminant Discriminant Number of Solutions Type of Solution Positive, perfect square Two Rational Positive, but not a perfect square Irrational Zero One (a double solution) Negative Nonreal complex

Caution The restriction on a, b, and c is important Caution The restriction on a, b, and c is important. For example, for the equation the discriminant is b2 – 4ac = 5 + 4 = 9, which would indicate two rational solutions if the coefficients were integers. By the quadratic formula, however, the two solutions are irrational numbers,

For 5x2 + 2x – 4 = 0, a = 5, b = 2, and c = – 4. The discriminant is USING THE DISCRIMINANT Example 9 Determine the number of distinct solutions, and tell whether they are rational, irrational, or nonreal complex numbers. a. Solution For 5x2 + 2x – 4 = 0, a = 5, b = 2, and c = – 4. The discriminant is b2 – 4ac = 22 – 4(5)(– 4) = 84 The discriminant is positive and not a perfect square, so there are two distinct irrational solutions.

First write the equation in standard form as USING THE DISCRIMINANT Example 9 Determine the number of distinct solutions, and tell whether they are rational, irrational, or nonreal complex numbers. b. Solution First write the equation in standard form as x2 – 10x + 25 = 0. Thus, a = 1, b = – 10, and c = 25, and b2 – 4ac =(– 10 )2 – 4(1)(25) = 0 There is one distinct rational solution, a “double solution.”

For 2x2 – x + 1 = 0, a = 2, b = –1, and c = 1, so USING THE DISCRIMINANT Example 9 Determine the number of distinct solutions, and tell whether they are rational, irrational, or nonreal complex numbers. c. Solution For 2x2 – x + 1 = 0, a = 2, b = –1, and c = 1, so b2 – 4ac = (–1)2 – 4(2)(1) = –7. There are two distinct nonreal complex solutions. (They are complex conjugates.)