Expert: Lynn Houston - 9/24/2008

Question
My son and I are trying to find the equation of a line perpendicular to a given
line.  There are, of course, no examples in his workbook and we need some
help.  We are given...y=3x+2 and we need to find the equation for a
perpendicular line...Thank you in advance.

Answer
If you are not given any points that the perpendicular line has to go through, then y = -1/3x + 2 would work.  Perpendicular lines have negative, inverse slopes.  The slope of the first line is 3, so the negative inverse slope would be -1/3.  The lines whose eqs are y=3x+2 and y = -1/3x + 2 would intersect at (0,2) and be perpendicular.