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avatar+846 

Hi friends,

I have something that tickles me..laugh..please help:

 

if I look at \(x^2-4x-5=0\)

and I wanted to check the nature of the roots by solving the equation, it would be like this:

\((x+1)(x-5)=0\)

\(x=-1\)  or  \(x=5\)

 

So all I can really say is that the roots are un-equal

 

However doing it this way:

\(\Delta =b^2-4ac\)

    \(=(-4)^2-4(1)(-5)\)

    \(=16+20\)

    \(=36\)

 

which means the roots will be real, un-equal and rational...However, the roots do only seem to satisfy the "un-equal" nature?

 Jun 2, 2021
 #1
avatar+121054 
+1

Notice though  that b^2  -4ac    is  under  a radical......so    sqrt (36)  =  6

 

So.....the roots will   be real,  rational   AND unequal

 

cool cool cool

 Jun 2, 2021
 #2
avatar+846 
+1

Hi CPhill,

 

thank you for the response, I guess I'm getting thrown off track with the fact that I thought the roots had to be squares themselves. my error, thank you kindly..

juriemagic  Jun 2, 2021

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