The first is the simplest absolute value function image, as shown below.
Concept of absolute value: |a|= When a > 0, a; When a=0, 0; When a < 0,-a.
Two points a and b on the coordinate axis are symmetrical about x. If A(x0, y0), then B(x0, -y0).
Function translation law: add left and subtract right, add up and subtract down.
The function f(x+m) can be regarded as the translation of the function f(x) by m units along the x axis (i.e. in the horizontal direction). If m > 0, it is translated to the left, and if m < 0, it is translated to the right.
The function f(x)+m can be regarded as the translation of the function f(x) by m units along the y axis (i.e. vertical direction). If m > 0, the translation is upward. If m < 0, it is translated downward.
The picture comes from the internet.
The above is the knowledge about absolute value function. Of course, there are still some marginal knowledge that has not been mentioned, but these are enough to deal with the problems in junior high school. Come on!