Posted by **Diana** on Thursday, June 17, 2010 at 10:29pm.

How can you determine if two lines are perpendicular?

- Math -
**Reiny**, Thursday, June 17, 2010 at 10:47pm
find their slopes.

If the are the opposite reciprocals of each other, they are perpendicular.

or

if their product is -1 they are perpendicular.

- Math -
**Diana**, Thursday, June 17, 2010 at 10:50pm
thank you, But what if the product is something other than -1 Could it still be perpendicular? Why or Why not?

- Math -
**Reiny**, Thursday, June 17, 2010 at 11:12pm
nope, if the product is not -1, they are not perpendicular

If the slopes are opposite reciprocals, their product will always be -1. So that is the basic condition.

e.g. slope of first = 4/5

slope of second = -5/4

(4/5)(-5/4) = -1

- Math -
**Diana**, Thursday, June 17, 2010 at 11:39pm
Thank you!

## Answer this Question

## Related Questions

- MATH - Post your 50 or more word response to the following in the assignment ...
- MATH - How can you determine if two lines are perpendicular? · How the slopes of...
- math needed by 12midnight - How can you determine if two lines are ...
- algebra need by 10p cst - How can you determine if two lines are perpendicular? ...
- alg. - Determine which two equations represent perpendicular lines. a) y=2x - 6 ...
- geometry - Martin drew a pair of perpendicular lines and a pair of parallel ...
- Math - Two points for each of two lines are given. Determine if the lines are ...
- math - parallel and perpendicular lines Determine an equation of each of the ...
- math - are these two lines perpendicular? x+2y=5 2x+4y=7 How do I determine if ...
- math - are these two lines perpendicular? x+2y=5 2x+4y=7 How do I determine if ...

More Related Questions