Question 967375
Say the slopes are {{{ m[1] }}} and {{{ m[2] }}}
In order to be parallel,
{{{ m[2] = m[1] }}}
----------------------
In order to be perpendicular,
{{{ m[2] = -1/m[1] }}}
---------------------
The slopes of these equations are
neither parallel nor perpendicular
------------------------------
Here's the plots:
{{{ graph( 400, 400, -10, 10, -10, 10, -2x + 4, 2x + 4 ) }}}