<< Chapter < Page Chapter >> Page >
This module is from Elementary Algebra</link>by Denny Burzynski and Wade Ellis, Jr. Methods of solving quadratic equations as well as the logic underlying each method are discussed. Factoring, extraction of roots, completing the square, and the quadratic formula are carefully developed. The zero-factor property of real numbers is reintroduced. The chapter also includes graphs of quadratic equations based on the standard parabola, y = x^2, and applied problems from the areas of manufacturing, population, physics, geometry, mathematics (numbers and volumes), and astronomy, which are solved using the five-step method.This module provides a summary of the key concepts from the chapter "Quadratic Equations".

Summary of key concepts

Quadratic equation ( [link] )

A quadratic equation is an equation of the form a x 2 + b x + c = 0 , where a 0. This form is the standard form of a quadratic equation.

a is the coefficient of x 2 .
b is the coefficient x .
c is the constant term.

Zero-factor property ( [link] )

If two numbers a and b are multiplied together and the resulting product is 0, then at least one of the numbers must be 0.

Solving quadratic equations by factoring ( [link] )

  1. Set the equation equal to 0.
  2. Factor the quadratic expression.
  3. By the zero-factor property, at least one of the factors must be zero, so, set each factor equal to zero and solve for the variable.

Extraction of roots ( [link] )

Quadratic equations of the form x 2 K = 0 or x 2 = K can be solved by the method of extraction of roots. We do so by taking both the positive and negative square roots of each side. If K is a positive real number then x = K , K . If K is a negative real number, no real number solution exists.

Completing the square ( [link] )

The quadratic equation a x 2 + b x + c = 0 can be solved by completing the square.
  1. Write the equation so that the constant term appears on the right side of the equal sign.
  2. If the leading coefficient is different from 1, divide each term of the equation by that coefficient.
  3. Find one half of the coefficient of the linear term, square it, then add it to both sides of the equation.
  4. The trinomial on the left side of the equation is now a perfect square trinomial and can be factored as ( ) 2 .
  5. Solve the equation by extraction of roots.

Quadratic formula ( [link] )

The quadratic equation a x 2 + b x + c = 0 can be solved using the quadratic formula.

a is the coefficient of x 2 .
b is the coefficient of x .
c is the constant term.

x = b ± b 2 4 a c 2 a

Parabola ( [link] )

The graph of a quadratic equation of the form y = a x 2 + b x + c is a parabola.

Vertex of a parabola ( [link] )

The high point or low point of a parabola is the vertex of the parabola.

Questions & Answers

calculate molarity of NaOH solution when 25.0ml of NaOH titrated with 27.2ml of 0.2m H2SO4
Gasin Reply
what's Thermochemistry
rhoda Reply
the study of the heat energy which is associated with chemical reactions
Kaddija
How was CH4 and o2 was able to produce (Co2)and (H2o
Edafe Reply
explain please
Victory
First twenty elements with their valences
Martine Reply
what is chemistry
asue Reply
what is atom
asue
what is the best way to define periodic table for jamb
Damilola Reply
what is the change of matter from one state to another
Elijah Reply
what is isolation of organic compounds
IKyernum Reply
what is atomic radius
ThankGod Reply
Read Chapter 6, section 5
Dr
Read Chapter 6, section 5
Kareem
Atomic radius is the radius of the atom and is also called the orbital radius
Kareem
atomic radius is the distance between the nucleus of an atom and its valence shell
Amos
Read Chapter 6, section 5
paulino
Bohr's model of the theory atom
Ayom Reply
is there a question?
Dr
when a gas is compressed why it becomes hot?
ATOMIC
It has no oxygen then
Goldyei
read the chapter on thermochemistry...the sections on "PV" work and the First Law of Thermodynamics should help..
Dr
Which element react with water
Mukthar Reply
Mgo
Ibeh
an increase in the pressure of a gas results in the decrease of its
Valentina Reply
definition of the periodic table
Cosmos Reply
What is the lkenes
Da Reply
what were atoms composed of?
Moses Reply
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Elementary algebra. OpenStax CNX. May 08, 2009 Download for free at http://cnx.org/content/col10614/1.3
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Elementary algebra' conversation and receive update notifications?

Ask