SOLUTION: How can you determine if two lines are perpendicular?

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Question 220241: How can you determine if two lines are perpendicular?
Found 2 solutions by solver91311, jim_thompson5910:
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


It depends on what information you have about the lines. Not knowing your starting point, all I can say is the following:



John

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
If their slopes multiply to -1, then they are perpendicular lines. Or another way to say it: Given a slope m, the perpendicular slope would be -1%2Fm. So if one slope is the negative reciprocal of the other, then they are perpendicular.

Example: I claim that the lines y=2x and y=-%281%2F2%29x are perpendicular. How do I prove this? Just multiply the two slopes 2 and -1%2F2 to get 2%28-1%2F2%29=-2%2F2=-1. So my claim is verified.