Question

What would the inequality be that represents this graph? And could someone explain it to me a bit, also? :/

http://imgur.com/0xVJtJN

Answer 1

\[y \ge mx + c\] u guys agree with this? all there is left to do i find m and c

Answer 2

@Zendemi15 u know how to find c and m?

Answer 3

No
:/

Answer 4

sry for the late reply

Answer 5

m is the gradient, and c is the y intercept, right?

Answer 6

its okay

Answer 7

yes :)

Answer 8

Ok the gradient would be 0.5 then, right?

Answer 9

so lets find c first, at wat pt does the graph touch the y-axis?

Answer 10

0,-1 i think?

Answer 11

wat were the two pts u chose to get that gradient?

Answer 12

correct :) so c = -1 :)

Answer 13

so y = mx - 1 is wat we found so far

Answer 14

okay

Answer 15

how did u get that gradient?

Answer 16

a chart thing my teacher showed me, about how the gradient is pretty much the steepness of the line and all that

Answer 17

well ur teacher told u crap xD

Answer 18

ill show i how to find the gradient of the line ;)

Answer 19

Lol okay

Answer 20

\[m=\frac{ y _{2}-y _{1} }{ x _{2}-x _{1} }\]

Answer 21

u r familiar with this formula?

Answer 22

kinda

Answer 23

that means no in my book so ill show u how to use it

Answer 24

Lol okay xD

Answer 25

ok so how this formula works is that u choose any two points on the line and plug in it's y and x value

Answer 26

ok

Answer 27

so u choose two pts now :P

Answer 28

-2,-2 and 2, 2

Answer 29

those rnt points on the line

Answer 30

u have to choose two pts on the line (the line connecting the two arrow heads) not the pink region

Answer 31

understand?

Answer 32

Yeah.. I'm just tired and it's taking me a while to think lol
2,1 and 1,1

Answer 33

i can understand that, would u rather i ust did it for u and explain wat i did?

Answer 34

Yeah and then ill look over it again tomorrow so I'll understand it better

Answer 35

and those rnt pts on the line either

Answer 36

u want to go through it with me tomorrow as well?

Answer 37

Yeah that would be great

Answer 38

fine by me :) wat time will u be on?

Answer 39

eh after i explain it ill organise that lol

Answer 40

ok back to the question :)

Answer 41

now ignore th pink region and just focus on the red arrow, cool?

Answer 42

Alright

Answer 43

0,-1 and 1,-1? o.O

Answer 44

1, -1 isn't on the line

Answer 45

look for places where the line crosses over an intersection of lines on the grid exactly.

Answer 46

Just so the graph is a bit clearer.

Answer 47

This is probably wrong, but 2,-2 and -3,3?

Answer 48

do you know how to find the equation of a line?

Answer 49

http://www.mathsisfun.com/equation_of_line.html

Answer 50

oh, I see. you need to know how to find the slope.
Start at the point you already found, (0, -1)
Move along the line until you find another point with integers as y and x values
m= the horizontal distance you went / the vertical distance you went

Answer 51

The dashed line intersects the point (0,-1) which means that the y-intercept is -1.

To get the slope from the graph, I looked for two points both with integer coordinates that appear to be points on the dashed line.

I chose (-3,-3) and (0,-1). From (-3,-3) I counted 3 units to the right to get underneath the point (0,-1). That took me to the point (0,-3) from which I counted 2 units up to reach the point (0,-1).

For slope, the change in x is 3, and the change in y is 2. The slope of the dashed line is 2/3.

Using the slope-intercept form of a line: y = mx + b, then the equation of the dashed line is y = (2/3) x - 1.

The shaded section is above the dashed line. Its equation is y > (2/3)x - 1. -->

Please check my work. @Zendemi15