Need Help with calc Hw!

ethandf06

ethandf06

Wizard
Visit site
So I have been messing with this problem forever and I cont figure it out for the life of me. Hopefully there is a math whizz lurking on the forum. I need it finished by 10 tomorrow:frown:. Here is the question find a function f(x) that is continuous at x=1,2 and 3 but not differentiable at x=1,2 and 3. Comment: it has to be one such function not three functions. I can repay you for your efforts in beer:icon_beer:
 
The derivative of an absolute value function is difficult or undefined. At values 1, 2, and 3, the function is defined, of course, and so is continuous. But the derivative? I don't off-hand know what it is. Is the derivative possible at a point?
If you are using the definition of continuous as a derivative existing at the point in question, then .... if there is none - your answer is noncontinuous at that point. But you know that the absolute value function actually is continuous by substitution of values. It's just kind of a riddle to me - off-hand -- without more thought.

f(x)=abs(x)

That would be a last minute desperate attempt - from me. It's late - can't sleep - but I've gotta. Would be nice to be able to think about it in more detail.
And you have got 10 AM looming.

That's all I've got for you.

Let us know. I'm curious.
 
Last edited:
To quote a line from some movie:

You guys are just "Mentally Playing With Yourselves".

I think Shag and Wikipedia have hit on the answer.
 
Found it out this morning after some sleep. F(x)=|x-1|+|x-2|+|x-3|.

Here it is on wolffram alpha.

B7365092-4796-42D5-9A48-981917616B09-4646-000001F22D34731B_zpscd3fb05d.jpg
 
I'm retired and don't have to worry about that stuff any more. My hardest calculation now is how many mpg I'm getting on the bike. Age has it's advantages.
 
Evitzee said:
I'm retired and don't have to worry about that stuff any more. My hardest calculation now is how many mpg I'm getting on the bike. Age has it's advantages.
Click to expand...

You don't want to do that calculation (MPG) on a V-Max! Ignorance is bliss! :wilynily:

Glad you figured out the problem. Ah, calculus. I don't remember much about it now. I did take the class. :nerd:
 
Yea, I took plenty of Calculus back in college (I, II and III), but unfortunately I don't really use it in my line of work so have forgotten most of it :(
 
Blanchy said:
You all make me feel incredibly stupid. I have no idea what anything in this post refers too!
Click to expand...

It's just stuff... don't feel that way.

You would understand if it was explained to you. But it would take quite a while - 'cause there is a lot of background to make up.
 
You must log in or register to reply here.
Back
Top