Question

Find the equation of a line that is perpendicular to the line y=1/8x +8 and contains the point (-2,0).

Answer 1

Perpendicular lines have their slopes as a flipped fraction of the original slope and opposite signed.

A perpendicular line to an equation with a slope of (2/5) would have a slope of (-5/2)

Answer 2

What is the slope of the equation you posted?
Flip the fraction and make it negative to find the slope of the perpendicular equation.

Answer 3

*the slope is always the number next to x

Answer 4

The slope of the equation is (1/8) so a perpendicular slope would be -8

Answer 5

-8x +8

Answer 6

Ignore the +8, that's the y=intercept of the original equation.

Answer 7

ok

Answer 8

Now we use point-intercept form.

y-(y1)=m(x-x1)

Using the point (-2,0). 0 is y1, m is perpendicular slope (-8), and x is -2

Answer 9

y-0=-8(x-(-2)

solve the equation for y

Answer 10

Can you do that?

Answer 11

trying to solve it.... a bit slow but getting there

Answer 12

y=-8x +16

Answer 13

y-0=-8(x-(-2))
y-0=-8(x+2)

x-(-2) = x+2

Answer 14

You are close, it should be y=-8x-16 (double checking)

Answer 15

y=-8(x+2)
y=-8x-16

Answer 16

sure negative 8 times positive 2 is negative 16. got it. thx

Answer 17

i always miss that

Answer 18

People get confused with x-negative number,

Minus a negative is a positive.

Answer 19

Will remember that. thx.

Answer 20

Thanks larrybox for simplifying this for me. you sure made it easy to understand.

Answer 21

In the eqation y=5x+5, what would be the perpendicular slope?

Answer 22

so what happens to the y intercept

Answer 23

meant -5x

Answer 24

Be careful, in this equation, the fraction is (5/1)

Answer 25

So the perpendicular slope would be (-1/5)

Answer 26

Nothing happens to the y-intercept, it just is not needed in calculation.

Answer 27

you know what? I thought about that but changed my mind. silly me!

Answer 28

Anything over 1 is itself. (5/1) 5, (-1/1) = -1

Answer 29

maths maths maths! not my strongest point at all

Answer 30

if the perpendicular slope for 1/8x = -8, then 5x = 5/1 would be -1/5

Answer 31

i should start saying math is interesting and gradually will get there! Thx lbp