Question

Write an equation of a line that passes through the given point and is perpendicular to the given line in slope intercept form (4,-5) y=2x+3

Answer 1

what is the slope of y = 2x+3

Answer 2

2x

Answer 3

close, it's just 2

Answer 4

that's the same as 2/1

Answer 5

my bad sorry.wouldnt it be -2/1 ??

Answer 6

to find the perpendicular slope, just flip the fraction and flip the sign

so flip the fraction to go from 2/1 to 1/2

then flip the sign to go from +1/2 to -1/2

this means that the perpendicular slope is -1/2

Answer 7

now you need to find the equation of the line that

a) has the slope of -1/2

and

b) goes through the point (4, -5)

Answer 8

AHHH!! I get it !!the new equation will be y=-1/2+3 now right?

Answer 9

no, that's not correct

Answer 10

no?

Answer 11

you start with y = mx+b and you plug in the slope (-1/2) and the given point (4,-5)

y = mx+b

y = (-1/2)x + b ... plug in the slope m = -1/2

-5 = (-1/2)(4) + b ... plug in x = 4 and y = -5

-5 = -2 + b

solve for b

Answer 12

b=-3

Answer 13

good, so the equation of the perpendicular line is \[\Large y = -\frac{1}{2}x - 3\]

Answer 14

Thank you so much!:D

Answer 15

you're welcome