How do you graph #y = | -1/4x -1|#?

2 Answers
Dec 4, 2017

graph{abs(-1/4x-1) [-10, 10, -5, 5]}

Explanation:

finding the point when y=0

#-1/4x-1=0#

then #x=-4#

when #x<=-4#

#abs(-1/4x-1)=-1/4x-1#

when #x> -4#

#abs(-1/4x-1)=1/4x+1#

both lines 'll be draw

#y=-1/4x-1#

finding y-intercept when x=0

#y=-1# then the point to ubicate #(0,-1)#

when y=0
#x=-4# the point is #(-4,0)#

for #y=1/4x+1#

y-intercept is when x=0
#y=1# #(0,1)#

x-intercept is when y=0
#x=-4# #(-4,0)#

Dec 4, 2017

if x=0 then y=1
if x=-4 then y=0
if x=-8 then y=1 (as well)

Explanation:

Absolute value mirrors everything that is in negative numbers to the positive numbers.
I simply draw a net. Then put instead of x a number. For example:
x=0 then y=1
if x=-4 the y=0
Now you can draw a line that goes through this two points. The other part will be mirrored just like the right side. Let's see.
Let's put instead of x a number -8. Then y=1 just as for the x=0.
Hope it helps.
There is also a way to split this function into two(a bit useless for this particular example).
#f_1: y=-1/4x-1# for #x>=0#
#f_2: y=1/4x+1# for #x<0#
Hope it helps