Question

I have a few problems where you are given a point and an equation and you have to find an equation that is either parallel or perpendicular. I just don't get it at all...

Answer 1

parallel : the same slope
perpendicular : slope flip and opposite site

Answer 2

I know, but what am I to do with the points I'm given? Do I plug them in the equation or what? I'm confused.

Answer 3

give me a example

Answer 4

Okay. One of them is Find an equation of the line meeting the specified conditions. Write the final answer in slope-intercept form.

Containing the point (2,6) and parallel to y=-4x-1

Answer 5

y=-4x-1 if parallel use the same slope : -4
and creative another line
y -6 = -4(x - 2)
y -6 = -4x +8
y = -4x +8 +6
y = -4x + 14 now

line : y=-4x-1 parallel to line
y = -4x + 14

Answer 6

-4 is slope
14 is y intercept

Answer 7

how do you get the slope when there's only one given pair of points?

Answer 8

use the frist equation slope y=-4x-1
slope is -4

Answer 9

Okay. That makes so much more sense now. Thanks.

Answer 10

The slope between two points is
\(\frac{y_2-y_1}{x_2-x_1}\)

Answer 11

one given pair use slpoe = 6/2 or 3

Answer 12

If you have the equation for a line y = mx + b, m is the slope.

Answer 13

So, let's say I have one that has the points (0,-5) and perpendicular to y=6x + 8. How would I go about solving that?

Answer 14

What is the slope for that line y=6x+8?

Answer 15

given what I said before about m?

Answer 16

y=6x + 8 perpendicular use 6 flip = 1/6 and negative side is : - 1/6
y- (-5) =-1/6( x- 0)
y +5 = -1/6x
y = -1/6x -5
line: y=6x + 8 is: perpendicular to
y = -1/6x -5

Answer 17

Thanks so much. That has helped a lot.

Answer 18

you are welcome

Answer 19

Now, what if I have a problem where it only has y? For example, points (0,-9) and parallel to 4y=8

Answer 20

Solve for y.

Answer 21

If 4y=8 then y=?

Answer 22

I know y=2 but I'm lost as to what to do next

Answer 23

Ok, well. Going back to the form y=mx + b, what is your m?

Answer 24

would it be 0? or undefined?

Answer 25

It would be 0. y = 0x + 2 = 2

Answer 26

y=2 is a straight horizontal line that goes through the y axis at y=2 and doesn't increase or decrease with a change in x.

Answer 27

So the slope is 0. Now to find a new line that is parallel means that the new line has the same slope.

Answer 28

But instead of going through y=2, it goes through y=-9

Answer 29

I ended up with y=0x -9 but I'm not sure if that's right?

Answer 30

Yes, now simplify.

Answer 31

4y=8
y = 2 slope =0
y-9= 0(x-0)
y = 9
line 4y=8 parallel to line y = 9

Answer 32

Should be y=-9

Answer 33

y=-9 if you want perpendicular to line 4y=8

Answer 34

No. y=-9 is parallel to the line y=2. They both have a 0 slope. One intersects (0,-9) the other intersects (0,-9)

Answer 35

One intersects(0,-9) and the other intersects(0,2) rather

Answer 36

I also got y=-9

Answer 37

A perpendicular line would have an undefined slope -1/0

Answer 38

I forgot negative 9
y=-9 is right amswer