1 algebra question??!!! please help!

Question

jen543 · Answer

use the graph of the function to find its average rate of change from x=-1 to x= 3
simplify your answer as much as possible

hexiflexidexi · Answer

Try finding the coordinates of the function when x=-1 and x=3 :)

jen543 · Answer

I'm really not sure, I completely forgot all this stuff

misty1212 · Answer

Hi!!

misty1212 · Answer

what is y where x = -1?  
they have the point labelled for you

jen543 · Answer

0?

misty1212 · Answer

?

misty1212 · Answer

$(-1,0)$ is not on the graph

hexiflexidexi · Answer

The y coordinate is the position of the dot on the vertical axis~

jen543 · Answer

Oh is it -2?

kayders1997 · Answer

Good so. You have the coordinate (-1,-2) now we need to find the y value at 3

jen543 · Answer

6?

kayders1997 · Answer

Yes so your other coordinate is (3,6)

kayders1997 · Answer

Now the average rate of change means slope, do you know that equation?

hexiflexidexi · Answer

The average rate of change means the slope of the line connecting the two points :)

jen543 · Answer

the average rate of change formula?

kayders1997 · Answer

Or slope same thing

hexiflexidexi · Answer

Yea. The slope of any two points :)

jen543 · Answer

y=mx+b

hexiflexidexi · Answer

Yea. That's the equation of the line. but do you know how to calculate the slope from any given two points?

jen543 · Answer

uhhhh I would probably remember, completely forgot this stuff.. I did it a while ago

hexiflexidexi · Answer

It's rise over run (change in y over change in x) :) Do you remember now?

jen543 · Answer

riggght!

kayders1997 · Answer

M=y2-y1
     -------
      X2-x1

jen543 · Answer

Ohh okay cool, so I plug in those values and solve?

hexiflexidexi · Answer

Yep :)

kayders1997 · Answer

Yes just make sure you put the numbers into the correct spots so if you call the first point 1 than the x and y need to both go in the X11 and y1 spots

jen543 · Answer

So 2/4?

kayders1997 · Answer

Close I think you mixed up the y and x part y goes on top

jen543 · Answer

oh oops my bad, 4/2

kayders1997 · Answer

That is what I got, good job :)

jen543 · Answer

So would that be the average rate of change???

kayders1997 · Answer

Correct

jen543 · Answer

oh okay, would I simplify it to 1/2??

kayders1997 · Answer

What is 4/2 :)

jen543 · Answer

2

kayders1997 · Answer

Yes

jen543 · Answer

Oh okay so the average rate of change is 2, thank you very much!!

kayders1997 · Answer

No problem :)