Question

Which is greater? Line l has slope > 1.

A. Slope of line p

B. -1

Answer 1

The answer is A i need to know why

Answer 2

@phi

Answer 3

the slope of p is -1/m (negative reciprocal of line 1 which I assume as slope "m")
we know this because the two lines are perpendicular (from the little square they drew)

Answer 4

Is that some type of rule?

Answer 5

Rule with the perpendicular?

Answer 6

line 1 has slope m> 1
so let's pick m= 2 which is bigger than 1 (as a "for example")

the line p has slope -1/2

which is bigger -1 or -1/2
-1/2 is bigger (I hope that is clear)

Answer 7

**Is that some type of rule? ***
more like a fact... we can prove it.

Answer 8

wait let me clarify this. So for perpendicular slopes it's always the opposite right? if the slope is 1/3 then the perpendicular slope is -3 am i right?

Answer 9

yes. the only time we run into a problem is a horizontal line with slope 0
and a vertical line with "undefined" slope. we could use the rule and get -1/0
but we are not allowed to divide by 0, so we just say "undefined"

but other than that it's
for example

1 , -1
2 , -1/2
-3/2 , 2/3
-5, 1/5

when you multiply them you will get -1

Answer 10

OHHHHHHHHHHHHHHHHHHHHHHHHHHHHH okay i got it now <3333333333333333