Solving Quadratic Equations By The Quadratic Formula

Solving Quadratic Equations

Looking at an example:

You are given the question

x²+5x+4=0

In the above example,

a=1 (If there is no number before the x then we can assume that thenumber is 1)

b=5

c=4

What we then have to do is find out what x could be equal to in order to satisfy the equation and therefore make it true. In this example, x can either equal -4 or -1 . We don't know yet how we came to this answer, but let's show that both of these answers do work.

Putting -4 into the above equation:

x²+5x+4=0

(-4)² + (5*-4) + 4 = 0

(-4)*(-4)  + (5*-4) + 4 = 0

16 + (-20) + 4 = 0

16-20+4=0

-4+4=0

0=0

This shows that -4 can be a solution for x

Putting -1 into the above equation:

x²+5x+4=0

(-1)² + (5*-1) + 4 = 0

(-1)*(-1)  + (5*-1) + 4 = 0

1 + (-5) + 4 = 0

1-5+4=0

-4+4=0

0=0

This shows that -1 can also be a solution for x

Therefore, there are two possible solutions, -1 and -4. They must both begiven as an answer to obtain full marks.

Once you have obtained the possible solutions for x, is is always necessary to checkthem in the above way

Let's teach pupils about real life - Irish Independent

Let's teach pupils about real life Irish Independent, Ireland - Jun 7, 2008 ... how money actually works would be far more beneficial than hours spent trying to find the solution of quadratic equations with rational coefficients. ...

Yale schools have made huge strides - Port Huron Times Herald

Yale schools have made huge strides Port Huron Times Herald, MI - Jun 15, 2008 They calculate minimum/maximum values and use factoring, completing the square and quadratic formula to locate the x-intercepts of parabolas. ...

Maths was a pleasant surprise, but it all counts for nothing if ... - Irish Independent

Maths was a pleasant surprise, but it all counts for nothing if ... Irish Independent, Ireland - Jun 6, 2008 I was raring to go and keen not to be caught off guard by some quadratic equation in question two or three. But caught out I was, and when I was shown how ...

The Derivation of "Logistic-shaped" Discovery - The Oil Drum

The Derivation of "Logistic-shaped" Discovery The Oil Drum - Jun 26, 2008 The post addresses the origins and relevance (or lack thereof) of the logistic equation as it is commonly used in projecting/modeling oil production ...

Math camp gives girls equation on how - Greeley Tribune

Math camp gives girls equation on how Greeley Tribune, CO - Jun 20, 2008 As the math professor wrote a quadratic equation on the chalkboard, girls around the room volunteered correct numbers to plug into the complex formula. ...

HPF Hangover Prevention Formula and the Prickly Pear Who Went to Medical School To Prevent Hangovers.

VISTA, Ca (PRWEB) July 22, 2004 -- Now a patented herbal extract (named Tex-OEŽ) is the first and only product clinically proven to prevent hangover symptoms. It's a fact. No other product has...

The Real Prickly Pear Extract For Hangover Prevention

VISTA, Ca (PRWEB) July 22, 2004 -- Now a patented herbal extract (named Tex-OEŽ) is the first and only product clinically proven to prevent hangover symptoms. It's a fact. No other product has...

Sixty-Four Graduate Medical Students Got Drunk In The Name of Science

VISTA, Ca (PRWEB) July 22, 2004 -- Now a patented herbal extract (named Tex-OEŽ) is the first and only product clinically proven to prevent hangover symptoms. It's a fact. No other product has...

Only One Hangover Product Has Been Clinically Proven to Prevent Hangover Symptoms

VISTA, Ca (PRWEB) July 22, 2004 -- Now a patented herbal extract (named Tex-OEŽ) is the first and only product clinically proven to prevent hangover symptoms. It's a fact. No other product has...

FoliSolv(tm) Significantly Increases Bioavailability of Folic Acid in Nutritional Supplements

(PRWEB) February 8, 2005 -- Magno-Humphries Laboratories, Inc. announces the availability of a newly patented folic acid formula, FoliSolvTM (US Patent #6,248,361) by Integ LLC, for use in...

Yves Bodson, Photographer, presents "Quadratics: Art, Aesthetics and Mathematics" at Trifecta Gallery in Las Vegas, April 8-15, 2005.

(PRWEB) February 8, 2005 -- Magno-Humphries Laboratories, Inc. announces the availability of a newly patented folic acid formula, FoliSolvTM (US Patent #6,248,361) by Integ LLC, for use in...