Question #32820

1 Answer
Jan 21, 2016

Given

#l_1: y=m_1x+q_1#
#l_2: y=m_2x+q_2#

#l_1# // #l_2#

when:

#m_1=m_2#

Explanation:

An equation could be given in the follow forms:

  1. #y=mx+q#

#m# is the slope; #q# is the #y# axis intercept
2. #ay+bx+c=0#

This form could be write like the first one;
#y=-b/ax-c/a#
#=> m=-b/a; q=-c/a#

given:

#l_1: y=m_1x+q_1#
#l_2: y=m_2x+q_2#

#l_1# // #l_2#

when:

#m_1=m_2#

if #q_1=q_2#, then #l_1# is coincident with #l_2#

You have #l_1:y=6=>y=0*x+6=>m=0#

therefore the parallel lines to the given one are in the form:

#y=k =># all the horizontal lines