Graph of y=|x+1|+|2x-1|
Here's what you do, step by step:
Set the expressions inside the absolute value bars equal 0,
x+1 = 0 2x-1 = 0
x = -1 2x = 1
x =
These define three intervals: x < -1, -1 < x < 1/2, and x > 1/2
For x < -1, |x+1| = -(x+1) and |2x-1| = -(2x-1)
so y = -(x+1)-(2x-1) = -x-1-2x+1 = -3x
For -1 < x < 1/2, |x+1| = x+1 and |2x-1| = -(2x-1)
so y = x+1-(2x-1) = x+1-2x+1 = -x+2
For x > 1/2, |x+1| = x+1 and |2x-1| = 2x-1
so y = x+1+2x-1 = 3x-1-2x+1 = 3x
So the graph is this piecewise graph:
So draw the three lines:
Then erase the parts of the three lines that extend
past their part of the domain:
Edwin