solve the inequality. graph your solution. |x+3| > or equal to 15
Hint: |x| > k breaks into x < -k or x > k where k is some positive number
is it still correct if the arrows go in the same direction when I graph it?
no the arrows should be going in opposite directions
oh so you flip the sign when you make k a negative?
exactly
what did you get
x> or equal to 12 and x < or equal to -18
good, you got it
thanks :D
you're welcome
find the slope of the line passing through the given points. then tell whether the line rises, falls, is horizontal, or is vertical. (-7,4) (5,-3)
use the slope formula m = (y2 - y1)/(x2 - x1)
in this case (x1,y1) = (-7,4) (x2,y2) = (5,-3)
how do I find out whether the line rises, falls..etc ?
what did you get for the slope
-7/12
oh so the line decreases bc it has a negative slope?
you nailed it
Do you mind if i ask you questions from time to time ? I'm trying to study for a trig final on monday.
sure I can help
thanks! alright so this question has the same guidelines as the one we just did but with these coordinates (-5/4, 3); (2/3, 3) my friend had an error in her calculator trying to find the slope , but I got m=0 ...im confused
you're correct, it's 0 how do I know so quickly? notice that the y coordinates are both equal to 3 since the y coordinates are equal, the slope will always be 0 because you have a horizontal line through y = 3
all horizontal lines have a slope of 0
using m = (y2 - y1)/(x2 - x1) we get m = (y2 - y1)/(x2 - x1) m = (3 - 3)/(2/3 - (-5/4)) m = 0/(2/3 - (-5/4)) m = 0
oh ok i understand
what if the x coordinates are equal? would that make the line vertical?
exactly
and the slope would be undefined
oh okay
how would i graph y=|x-3|?
do you know how to graph y = | x |
i think so? would there be 2 lines?
yes here is your blank xy axis |dw:1359244103163:dw|
the graph of y = | x | looks like this |dw:1359244135745:dw|
to graph y=|x-3|, you just shift over y = |x| three units to the right
im not sure i get you there...
imagine you can pick up that v shaped graph and move it around well just move it over 3 to the right units like this |dw:1359244315265:dw|
but how do i know the coordinates to create the v shape
i understand the moving it to the right part
the sharp point on the V of y = |x| is at (0,0) move that point over 3 units to the right to get (3,0)
|dw:1359244469161:dw|
yes i understand that but what are the other coordinates for that shape?
for (3,0)..
(1,1) is on the original graph y = |x| move that 3 units to the right to get (4,1)
|dw:1359244638800:dw|
Join our real-time social learning platform and learn together with your friends!