Question

please help with piece wise graph

Answer 1

http://vvcap.net/db/Ea8WobNvpKnowqaCZesR.htp

Answer 2

Seriously, Sal? They're ALL lines!

Please pull out your 2-point form for a line and use it over and over and over.

Let's see what you get.

Answer 3

maybe im just that dumb

Answer 4

please explain

Answer 5

mx+b?

Answer 6

That is the Slope-Intercept Form of a line. You need the 2-Point Form of a Line. Do you have it?

Answer 7

no :(

Answer 8

That's not good at all.

Slope-Intercept: y = mx + b
Point-Slope: (y-y0) = m(x-x0)
Two-Point: (y-y0) = [(y1-y0)/(x1-x0)](x-x0)

Given

Slope = 5 and y-intercept = 3, we have

Slope-Intercept: y = 5x + 3

Given

Slope = 4 and point (2,6), we have

Point-Slope: (y-6) = 4(x-2)

Given

Point (3,1) and point (7,5), we have

Two-Point: (y-1) = [(5-1)/(7-3)](x-3)

Your piecewise definitions require the use of the two-point for. Identify two points on each line segement and you're nearly done.

Answer 9

\[f(x)=\left\{ x=3 ; 0 \le x \le 3\right\}\]?

Answer 10

thats for the first one, am i on the right path?

Answer 11

You're in the ballpark, but you are pointed the wrong way. Should be y = 4.

The next piece contains points (3,4) and (6,1)

Answer 12

am i going to have 4 set of points? 2 for each line? because i got

L1= (0,4) (3,4) L2= (3,4) (6,1)

Answer 13

That is correct. Except, just write down the vertical and horizontal ones.

(0,4)(3,4) should lead immediately to y = 4

Answer 14

just because both y1 and y2 are 4s? or do i have to plug them into some equation?

Answer 15

You can if you want. Or, you can just notice that those are easier and just write it down.

Same thing with equal x-values when you encounter those.

(2,3),(2,7) ==> x = 2 Done.

Answer 16

i give up. im not getting this.

Answer 17

Two Points. Put them in the 2-point form. It doesn't have to be harder than that.

Answer 18

I would use the y=mx+b.
For the first one there are two pieces:
y=4 is the first piece from x=0 to x=3.

Answer 19

For the second piece, you can look at rise over run to find the slope.
From the left-hand point (3,4), we go down three and then right three to get to the right-hand point (6,1).
That means the slope is 3/3 or 1, so m=1.

Answer 20

So far for y=mx+b, we have y=1x+b or simply y=x+b.
Now we can use one of the points to find b.
Using (3,4), x=3 and y=4. We subsitute those values into y=x+b.
4=3+b
Subtract 3 from both sides and b=4.
Now we have m and b to plug into y=mx+b.
The equation for our second piece is y=x+4.