Question

Choose the equation of the line passing through the point (4, -2) and perpendicular to y = 1/3x - 7.

y = -3x - 14

y = 3x - 10

y = -3x + 10

y = 3x + 14

Answer 1

the slope of your line is m = 1/3

so the slope of the perpendicular is -1/m

then when you have that use the point slope form

y = mx + b

and substitute x = 4 and y = -2 to find b

Answer 2

confused :/

Answer 3

ok... so if the slope of you given line is m = 1/3

what is -1/m

Answer 4

1/-3?

Answer 5

not quite... you need the negative reciprocal of 1/3 ...

Answer 6

-3/1?

Answer 7

correct or make it simple the slope of the perpendicular line is -3

so the line looks like

y = -3x + b

to find b, use the point (4, -2) and substitute x = 4 and y = -2 to get the value of b

Answer 8

ugh what do I do from there?

Answer 9

ok... replace x with 4 and y with -2 so you have

\[-2 = -3 \times 4 + b\]

you need to calculate the value of b

Answer 10

how do you calculate the value of B?

Answer 11

never mind I got it

Answer 12

ok... you if you simplify the equation above you ge

\[-2 = -12 + b\]

whats the value of b..?

Answer 13

10

Answer 14

so the equation is

y = -3x + 10

Answer 15

yeess :) thanks!