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Mathematics 9 Online
OpenStudy (anonymous):

Please help:)

OpenStudy (anonymous):

So I had to simplify \[\frac{ 4x ^{2}+7-2 }{ 4x-1 }\]that part is done but now it's asking explain why f(1) = 3, f(0) = 2, and f(-1) = 1, yet f\[\frac{ 1 }{ 4 }\] is undefined.

OpenStudy (anonymous):

well, if the denominator of a fraction is zero, then the number is undefined

OpenStudy (anonymous):

just looking at the denominator 4x-1 what happens if x=1/4?

OpenStudy (anonymous):

and i also assume its possible to cancel out the denominator, but that only works if what you're canceling out is equal to 1, not zero

OpenStudy (anonymous):

so it would be like this? 4 (1/4) -1=1?

OpenStudy (anonymous):

long story short 1/1= 1 0/0 is not 1

OpenStudy (anonymous):

... 4 times 1/4 is?

OpenStudy (anonymous):

in other words, 4 divided by 4 is?

OpenStudy (anonymous):

1

OpenStudy (anonymous):

ok now 1-1 is?

OpenStudy (anonymous):

0 which the reason it is undefined correct?

OpenStudy (anonymous):

ok now, lets look at trends 1/1= 1 1/.1 =10 1/.01 =100 1/.001=1000 so lets assume 0 is equivalent to a really really low number, like .0000000000000000000000001 so what happens when we get 1/0 ?

OpenStudy (anonymous):

Undefined?

OpenStudy (anonymous):

well, we get an infinitely large number or as some would call it, infinity but infinity is not an actual number, thus which is why we considered it undefined

OpenStudy (anonymous):

so basically, if you ever get a fraction whose denominator is zero, then the solution is undefined however, if you're dealing with limits, then its infinity a third note 0/0 is not equal to 1

OpenStudy (anonymous):

ok back to your previous question, do you think you can answer it now?

OpenStudy (anonymous):

Maybe only for the reason why 1/4 is undefined but not the others. I don't understand why it's asking to explain why f(1) = 3, f(0) = 2, and f(-1) = 1

OpenStudy (anonymous):

ok, so basically, what you were asked to simplify, is what is being considered as a function f(x) so when x =1, then the fraction is equal to 3 when x-0, then the fraction is equal to 2 your question is asking, why do those values have actual answers, when x=1/4 does not

OpenStudy (anonymous):

So pretty much it's like saying 4(1)-1=3 I don't get how f(0)=2 and f(-1)=1

OpenStudy (anonymous):

no, the function is the entire fraction, not just the denominator

OpenStudy (anonymous):

f(0)= (4*0^2-7(0)-2)/(4(0)-1)=?

OpenStudy (anonymous):

2 OH OKAY

OpenStudy (anonymous):

I get it now:)Thank you very much!!

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