Simplify expression

Posted on 2016-09-06
Last Modified: 2016-09-06
I don't understand it how it solved. Can you please do it in a different way.
Question by:mustish1
LVL 73

Accepted Solution

sdstuber earned 250 total points
ID: 41786941
it's just substitution.  There's really no trick or other method to it. In the example they skipped some of the trivial arithmetic; but we can show all of it.

f(4+h) - f(4)

solve it in two parts

part1: f(4+h) and then part2: f(4)  when you have both, subtract part 2 from part 1

part1:  x= 4+h

so  f(x) = x^2 - 2 = (4+h)^2 - 2 = 4^2 + 8h + h^2 - 2 = 16 + 8h + h^2 -2 = h^2 + 8h +14

part2: x = 4

f(x) = x^2 - 2 = 4^2 - 2 = 16 -2 = 14

f(4+h) - f(4) =    (h^2 + 8h + 14) -  (14) = h^2 + 8h
LVL 27

Assisted Solution

aburr earned 250 total points
ID: 41786946
What is f(x)?
f(x) = x^2 -2
What if x = 4 +h?      what is f(x) then?   It is
f(4+h) = (4+h)^2 -2
What if x= 4   What is f(x) then?    It is
f(4) = 4^2 = 16- 2 = 14   so

(4+h)^2 -2 = 14    do the square

16 + 8h + h^2 – 2 = 14          simplify

h^2 + 8h

Author Closing Comment

ID: 41786970
Thank You.

Featured Post

What Should I Do With This Threat Intelligence?

Are you wondering if you actually need threat intelligence? The answer is yes. We explain the basics for creating useful threat intelligence.

Join & Write a Comment

Suggested Solutions

If you want to move up through the ranks in your technology career, talent and hard work are the bare necessities. But they aren’t enough to make you stand out. Expanding your skills, actively promoting your accomplishments and using promotion st…
If you get continual lockouts after changing your Active Directory password, there are several possible reasons.  Two of the most common are using other devices to access your email and stored passwords in the credential manager of windows.
Notifications on Experts Exchange help you keep track of your activity and updates in one place. Watch this video to learn how to use them on the site to quickly access the content that matters to you.
Saved searches can save you time by quickly referencing commonly searched terms on any topic. Whether you are looking for questions you can answer or hoping to learn about a specific issue, a saved search can help you get the most out of your time o…

746 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

12 Experts available now in Live!

Get 1:1 Help Now