Question 524140
<pre>

{{{"f(x)"=system(matrix(1,3,-x,if,x>2),matrix(1,3,x-4,if,x<=2))}}}


The breaking point is at 2.  So draw a thin vertical line at x=2,
so you can erase it later:

{{{drawing(400,400,-7,9,-12,4,graph(400,400,-7,9,-12,4),
green(triangle(2,1,2,-2,2,-3))
 )}}}

Get a couple of points using values of x which 
are greater than 2 and use f(x) = -x:

 x | f(x)
 3 | -3
 4 | -4

{{{drawing(400,400,-7,9,-12,4,graph(400,400,-7,9,-12,4),
green(triangle(2,1,2,-2,2,-3)),

circle(3,-3,.1), circle(4,-4,.1) )}}}

Connect those points just up to the green line:

{{{drawing(400,400,-7,9,-12,4,graph(400,400,-7,9,-12,4),
line(2,-2,10,-10),

green(triangle(2,1,2,-2,2,-3)), circle(3,-3,.1), circle(4,-4,.1)  )}}}

--------------------------------------------

Get a couple of points using values of x 
which are less than 2 and use f(x) = x-4:

  x | f(x)
 -2 | -6
  1 | -3

{{{drawing(400,400,-7,9,-12,4,graph(400,400,-7,9,-12,4),
line(2,-2,10,-10), circle(-2,-6,.1), circle(1,-3,.1),

green(triangle(2,1,2,-2,2,-3)), circle(3,-3,.1), circle(4,-4,.1)  )}}}

Connect those points just up to the green line:

{{{drawing(400,400,-7,9,-12,4,graph(400,400,-7,9,-12,4),
line(2,-2,10,-10), circle(-2,-6,.1), circle(1,-3,.1),
line(-12,-16,2,-2),
green(triangle(2,1,2,-2,2,-3)), circle(3,-3,.1), circle(4,-4,.1)  )}}}

Erase the green lins:

{{{drawing(400,400,-7,9,-12,4,graph(400,400,-7,9,-12,4),
line(2,-2,10,-10), circle(-2,-6,.1), circle(1,-3,.1),
line(-12,-16,2,-2),circle(3,-3,.1), circle(4,-4,.1)  )}}}

Edwin</pre>