What is the slope of the line passing through the point (4, −3) and perpendicular to the line y = 2x + 1? Write your answer as a fraction.

Question

tkhunny · Answer

Why do we care what point it passes through?  If we just need the slope, then the "perpendicular" clue is quite sufficient.

We have y = 2x + 1.  The slope of this line is 2
How do we find the slope of a line perpendicular to this line?

anonymous · Answer

i dont know, if i remember correctly we would have to change the sign to negative?

tkhunny · Answer

What do you mean you don't know?  You are certainly on the right track.

Two easy ways to describe it.

1) Negative Reciprocal.  2 ==> -1/2  Done
2) Product is -1  2*What = -1, well "What = -1/2  Done.

anonymous · Answer

or make it 1/2?

anonymous · Answer

oh ok thx!! the first would be the easiest, i will use that

tkhunny · Answer

See, you had both pieces in your head.  That's the last of that "I don't know" stuff, right?!

anonymous · Answer

yup, thank you!