I have this function here.

Attachment 18564

Can someone please explain why from 4 < x < 10 it is 7 - x?

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- August 14th 2010, 06:31 AMrossy54newbie needing analytical description of a periodic function
I have this function here.

Attachment 18564

Can someone please explain why from 4 < x < 10 it is 7 - x? - August 14th 2010, 07:41 AMchiph588@
Well, two points make a line. Take the two endpoints and see what you get.

- August 14th 2010, 07:58 AMrossy54
not really sure. From 0 < x < 4 its 3x/4 but cant see why its 7 - x.

- August 14th 2010, 08:39 AMchisigma
You have a function...

(1)

... and is and ... then You can find and in 'standard way'...

Kind regards

- August 14th 2010, 03:53 PMVlasev
rossy54, the function changes from place to place. From 0 to 4 it is indeed 3x/4. However, it immediately changes to 7-x when x is between 4 and 10. After that it is a constant.

- August 14th 2010, 04:04 PMyeKciM
to make equation of line through two points :

now your two points

so you will have :D

if you don't trust me :D just put any x from 4 to 10 and you will get exact value of y...

for example x=7 -> y=0 (as you see on graphic)

:D

if u need to represent your function over step functions it would be like this :D

P.S. you can take any two points from that line and put in formula and you will get same result :D (doesn't have to be "start" and "end")