Question

Is the line through points P(-8, -10) and Q(-5, -12) perpendicular to the line through points R(9, -6) and S(17, -5)? Promised medal to helpful answer! c:

Answer 1

Can you find the slope of both pairs of lines?

Answer 2

@Ookami47

Answer 3

Hm. so ((-10) - )-12)) = -21 would equal the run right? ._. and the rise would be ((-8_ - (-5) = -13?

Answer 4

Would -13/-21 be one of the slopes? I'm just absolutely horrible when it comes to slopes..

Answer 5

no these lines arenot perpendicular because product of slope of these two lines should be -1means slope of PQ*slope of RS=-1

Answer 6

Yes that is correct. So the slope would be 13/21 right?

Answer 7

Now find the other slope.

Answer 8

@CUTE_AKKI : I was getting to that but I wanted him to do out the work :P .

Answer 9

-8/11? o:

Answer 10

Or am I backwards.. xD

Answer 11

Should be 8/1 or just 8 :) .

Answer 12

Oh. cx alrighty. What comes next?

Answer 13

Two lines are said to be Perpendicular if the slopes of both lines are negative reciprocals of each other.

Answer 14

As @CUTE_AKKI said.

Answer 15

Clearly, you can see they are not.

Answer 16

Obviously c:

Answer 17

So therefore, they are NOT Perpendicular :P .

Answer 18

Sweet! So I would just answer that they wouldn't be perpendicular due to the slopes not being negative reciprocals of each other?

Answer 19

ok....let m1 be slope of PQ =(-12-(-10))/(-5-(-8))=-2/3=m1
let m2 be slope of RS=((-5-(-6))/(17-9)=1/8=m2
now m1*m2 is not = -1 so given lines aren't perpendicular

Answer 20

Yeah.

Answer 21

I see... thank you for your help you guys. c: