Single variable calculus question. (first post)

  • Thread starter physicsstudent04
  • Start date

physicsstudent04

Hi I'm new to this forum.
I was wondering if anyone can explain to me how to do a first derivative test to find the relative extrema. I've been trying to read it, but it just isn't sinking in. thanks in advanced.
 

NateTG

Science Advisor
Homework Helper
2,449
5
If a function is continuous and differentiable then local maximums amd minimums occur where the graph of a function is flat, so they occur where the derivative is zero.

So, when looking for maximums and minimums you only need to check endpoints, and points where the derivative is zero or doesn't exist.
 

mathman

Science Advisor
7,689
389
There is third possibility for zero derivative points, horizontal inflection point. Example y=x3, at x=0.
 

physicsstudent04

thanks a lot guys. appreciate the help.
 

reinhard_t

please open the attachment below, to get better picture...
(note : that the picture is the graph f(x) against x )

actually to see the better idea of first derivative by imagining it as a gradient of the graph of a fuction.

suppose I have fuction f(x)

when you derive it becomes f'(x)...
what is f'(x) ???

f'(x) is the gradient.....

now look at the picture that there are 3 red straight lines.you can get line straight ,if and only if at the turning point like what you see in the graph

at the other point you will find the line is slope like both the blue line.

remember that straight line has gradient 0....that is to say, f'(x)=0

so to find either maxima or minima ,you must find value of x ,which can be subtituted into f'(x) and get value 0.
 

Attachments

Related Threads for: Single variable calculus question. (first post)

  • Posted
Replies
3
Views
3K
Replies
3
Views
8K
Replies
2
Views
3K
Replies
15
Views
2K
Replies
10
Views
14K
Replies
2
Views
594
Replies
11
Views
12K
Replies
1
Views
2K

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving

Hot Threads

Top