|x + 1| we set x + 1 = 0 and get x = -1, so
|x + 1| means x + 1 if x > -1 and -x-1 if x < -1
-------------------------
|2x - 1| we set 2x - 1 = 0 and get x =
, so
|2x - 1| means 2x - 1 if x >
and -2x +1 if x <
------------------------------
|x² + 1| means x² + 1 because x² + 1 is always positive.
------------------------------
|1 - 2x²| We set 1 - 2x² = 0 and get
-2x² = -1
x² =
x =
, so
|1 - 2x²| means 1-2x² if
< x <
and -1 + 2x² otherwise.
If this isn't what you mean, you can express what you mean
in the thank you note and I'll email you.
Edwin