Question

Choose the equation of the line passing through the point (-1, -2) and perpendicular to y = 1/4x + 2.


y = 4x - 6

y = -4x - 6

y = -4x + 2

y = 4x

Answer 1

take the negative reciprocal of the slope.
sub the given point in and solve for your constant.

Answer 2

......

Answer 3

first,can u find the slope of the given line y=1/4 x + 2?

Answer 4

i can find the slope if u give me 2 coordinates but not like that

Answer 5

@hartnn, she doesn't have to find the slope of that line. It's already given.

Answer 6

You're asking her the wrong question.

Answer 7

1/4

Answer 8

Yes @Gabylovesyou

Answer 9

ok.. now what lol

Answer 10

ok,i was trying to use the fact that slopes of perpendicular lines have product -1.....so that she gets slope of required line......

Answer 11

@Hero , help me out with my question? vectors are a nightmare for me

Answer 12

@hartnn now what?? the slope is 1/4

Answer 13

ok,since the product of slope of perpendicular lines is -1,can u find the slope of required line??

Answer 14

how??

Answer 15

let the slope of your line be m
since product is -1
m*(1/4)=-1
so m=-1*4 = -4
did u get this?

Answer 16

yessss

Answer 17

good,now we can take the slope-point form of the equation
y=mx+c
u found m as -4,only remaining work is to find c
to find c,we put the point (x,y)=(-1,-2)
like this:
-2=(-4)(-1)+c
can u find c from here?

Answer 18

-6

Answer 19

i think it's probably over 9000

Answer 20

yes,it is -6
so your equation y=mx+c with m=-4,c=-6 becomes
y=-4x-6
thats your 2nd option :)

Answer 21

thank you soo much!! :)

Answer 22

did u understand all the steps clearly?? ask if u still have doubts..

Answer 23

yea i did thanks soo much

Answer 24

welcome :)

Answer 25

i have to do another one of those :S

Answer 26

try it,if u don't get it,we are here :)

Answer 27

ok thanks

Answer 28

Choose the equation of the line passing through the point (-1, 7) and perpendicular to y = -1/4x - 5.

Answer 29

y = -4x - 11

y = -4x - 3

y = 4x + 11

y = 4x + 3

Answer 30

is it A

Answer 31

no,what did u find slope of 2nd line as?

Answer 32

-1/4 for the slope of y = -1/4x - 5.

Answer 33

so now what will be the slope of the line perpendicular to it?...remember that product of slopes of perpendicular lines = -1 as already told u

Answer 34

mmmmmm what would be the equation?

Answer 35

let the slope of your line be m
since product is -1
m*(-1/4)=-1
so m=-1*-4 = 4

Answer 36

OMG i knew it it was 4!!!

Answer 37

now put -1,7 in the equation y=4x+c to get c.....

Answer 38

7 = 4*-1 + C ??

Answer 39

C = 11 is the answer C

Answer 40

very good :) so whats the final answer?

Answer 41

third option??

Answer 42

yup :)