Lindsay O.

asked • 12/12/13

F(x)=6x+9 f(x-h)-f(x)÷h

F(x)=6x+9
F(x+h)-f(x)÷h
 

1 Expert Answer

By:

Don L. answered • 12/12/13

Tutor
4.9 (168)

Don - Math/Science Tutor from Elementary School to College level

See tutors like this
See tutors like this
just want to make sure if this is the setup you want to solve
it should setup as [F(x+h)-f(x)]÷ h
 
solve
 
F(x+h) = 6(x+h)+9 = 6x+6h+9
 
F(x) = 6x+9
 
 
[F(x+h)-f(x)] = 6x+6h+9 -(6x+9) = 6h
 
Therefore [F(x+h)-f(x)]÷ h = 6h÷ h = 6
 
answer is 6
Upvote • 1 Downvote
More
Report

Alex S.

So the derivative, as h approaches 0, is 6 .  This is likely the context of the question, right, Lindsay?
Report

12/12/13

Tom D.

Undoubtedly the correct interpretation.  Lindsay - pay attention to the way Don L. used parenthesis.
 
Parenthesis are CRITICAL for depicting contents following a division sign.  For example
 
f(x-h)-f(x)/h  DOES NOT EQUAL  [f(x-h) - f(x)]/h
 
The first expression merely divides f(x) by h.
The second expression is proper and divides the DIFFERENCE [f(x-h)-f(x)] by h
 
Think about this point carefully.  It will save a lot of heartache - especially as divisions become 'nested.'
Report

12/13/13

Still looking for help? Get the right answer, fast.

Ask a question for free

Get a free answer to a quick problem.
Most questions answered within 4 hours.

OR

Find an Online Tutor Now

Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.