Expressions involving f(x) notations  TOPIC_SOLVED

Complex numbers, rational functions, logarithms, sequences and series, matrix operations, etc.

Expressions involving f(x) notations

Postby jay79 on Sun Apr 12, 2009 10:36 pm

Hello,

I've been out of school for several years and now back in school
as I'm changing career fields.

I've signed up to seek help with some of my Pre-Cal math as I've
been struggling with ADHD. I'm properly medicated, but do require
step by step in order for math success.

I have an upcoming test this week and need to get a good grade.

One section I'm having some problems in relations to
is the Difference quotient.

It's the typical: f(x + h) - f(x)/h


This I am okay with, however it is examples such as these
that my book from Dawson College is useless. Our class average
is 41% and I received a 56% on the last test.

f(x) = X squared + x

Find:

a) f(2 + h) - f(2)/h

b) f(x) - f(2)/x-2


c) f(2+h) - f(2 -h)/2h

Do I subsitute only the f with xSquared + x???

Would example b) read: xSquared + x - 2/x-2

I also have no idea what to subsitute with example C)

I did what I thought was right and turns out to be incorrect
in our answer section.

One thing that doesn't help us is the fact that the faculty has
advised us of incorrect answers in our book (hand written I
might add). They unfortunately have no idea which answers
are wrong so this makes it even more confusing.

If someone can help, that would be greatly appreciated.

Thank you
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Postby stapel_eliz on Sun Apr 12, 2009 11:11 pm

I'm afraid I'm not quite clear on what you're saying...? :oops:

At a guess, I think you're having some difficulty with function notation. Many people do; I know I did, back in the day! :wink:

To learn how function notation works and how to evaluate a function at an expression (such as at "2 + h"), try here. :idea:
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Re: Expressions involving f(x) notations

Postby honest_denverco09 on Mon Apr 13, 2009 2:50 am

Sorry,There are some things that i don't get it.

i don't know what exactly do you want to solve ? Do you want to solve f(x) based on x or h ?

Under my assumption, i can help you as much as i can. Please refer my picture that is attached ! Hope it helps !

Image
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Re: Expressions involving f(x) notations

Postby Martingale on Mon Apr 13, 2009 4:14 am

honest_denverco09 wrote:Sorry,There are some things that i don't get it.

i don't know what exactly do you want to solve ? Do you want to solve f(x) based on x or h ?

Under my assumption, i can help you as much as i can. Please refer my picture that is attached ! Hope it helps !

Image



I don't think you want


you probably want
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Re: Expressions involving f(x) notations

Postby honest_denverco09 on Mon Apr 13, 2009 4:17 am

To affirm, maybe we need to wait for author! ^^ :D
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Re: Expressions involving f(x) notations  TOPIC_SOLVED

Postby Martingale on Mon Apr 13, 2009 4:35 am

honest_denverco09 wrote:To affirm, maybe we need to wait for author! ^^ :D


I agree!
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