Find the equation of the line passing through (4,3) and is
a) parallel
b) perpendicular
to the line -3x+y-5=0

Question

Find the equation of the line passing through (4,3) and is 
a) parallel 
b) perpendicular
to the line -3x+y-5=0

mertsj · Answer

-3x+y-5 = 0 has slope 3  The parallel line has the same slope so:  y-3=3(x-4)

The perpendicular has slope that is the negative reciprocal of 3 which is -1/3  So:  y-3= -1/3(x-4)

anonymous · Answer

how do you that the line passing through (4,3) has a slope of 3 ? how do you find it ?

anonymous · Answer

How do we find the equation of the line passing through (4,3) ?

mertsj · Answer

The problem says that the line has to be parallel to -3x+y-5=0

mertsj · Answer

That line has slope = 3.  Do you know that or not?

anonymous · Answer

yeah i know that -3x + y -5 =0 has a gradient of 3

mertsj · Answer

Well then a line parallel to it also has slope 3 and a line perpendicular to it has slope -1/3

mertsj · Answer

Do you understand now?

anonymous · Answer

Yes thanks a lot !

mertsj · Answer

yw