Absolute value graphs (1 Viewer)

Zuroy

New Member
Joined
Aug 2, 2009
Messages
15
Gender
Male
HSC
2011
What is the "quick" (faster) method of sketching absolute value graphs rather than doing the old 'table of values' method?

For example: Graph y = | x + 2 |
Should i just draw the graph of y = x + 2 but stop the line when it reaches 0 on the x-axis and then draw a reflection of that on the other side?

And for the question: y = 3x (without using a table of values since thats a bit slow)
How do i get the intercepts to plot of the graph when:
let x = 0 then y = 0
let y = 0 then x = 0
Some people are telling me to just memorize the shape of the graph but isnt that a little bit silly?



 

SeCKSiiMiNh

i'm a fireball in bed
Joined
Mar 6, 2008
Messages
2,618
Location
island of screaming orgasms
Gender
Male
HSC
2009
What is the "quick" (faster) method of sketching absolute value graphs rather than doing the old 'table of values' method?

For example: Graph y = | x + 2 |
Should i just draw the graph of y = x + 2 but stop the line when it reaches 0 on the x-axis and then draw a reflection of that on the other side?

And for the question: y = 3x (without using a table of values since thats a bit slow)
How do i get the intercepts to plot of the graph when:
let x = 0 then y = 0
let y = 0 then x = 0
Some people are telling me to just memorize the shape of the graph but isnt that a little bit silly?



i would draw the complete y= x+2 then rub out any parts under the x axis and draw the reflection of it. it's the fastest way imo.

and for the y= 3x thing, (0,0) is a point on the graph, yes. then let y =1, so x = 1/3 and connect the dots. basically, its like the y=x graph, but the slope is steeper.
 

mOusaa

New Member
Joined
May 4, 2009
Messages
5
Gender
Male
HSC
2009
no its not silly they are simple and you should memorise them to save time for example y=l x+2 l is the same as y=l x l moved two units to the left and intercepts the y axis at y=2
 

Lukybear

Active Member
Joined
May 6, 2008
Messages
1,466
Gender
Male
HSC
2010
If its stright, just memorise. Then translate via movement left or right, up or down.

If its curve, then draw and reflect.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top