Question

how do i find a point that is perpendicular to another line if I know what the equation of the first line is and i know what the slope is.

Answer 1

say the given slope is 2/3

Any line perpendicular to the given line will have a slope of -3/2

One way to remember this is to think "flip the fraction and flip the sign"

So....

Start with 2/3 (given slope)

flip the fraction: 2/3 ----> 3/2

flip the sign: 3/2 ----> -3/2


Therefore, if the given line has a slope of 2/3, then the slope of any perpendicular line is -3/2

Answer 2

Im sorry I dont really understand this how do I do the whole problem so that I can do the next 3

Answer 3

what's the full problem again?

Answer 4

what's all that you're given?

Answer 5

If the line h passes through the two points (1, 2) and (3, 6) This is the given information to solve the two problmes, here is the questions


What is the slope of the line h passing through the two points?
What is the equation of the line h passing through the two points?
If line g passes through point (2, 2) and is perpendicular to the line h, then what is the equation of
line g ?

Answer 6

how far did you get here?

Answer 7

were you able to find the slope of the line h?

Answer 8

i got that the equation of line h passing through is Y=2x

Answer 9

good

Answer 10

so the slope is 2 or 2/1

Answer 11

and the slpe is 2

Answer 12

so what's the perpendicular slope?

Answer 13

If line g passes through point (2, 2) and is perpendicular to the line h, then what is the equation of
line g ? this is the one that I am having trouble with

Answer 14

if the slope is 2 or 2/1

then what's the perpendicular slope?

Answer 15

hint: look at my steps in my very first post

Answer 16

I really do not like math i am so slow to learn this stuff

Answer 17

that's ok

Answer 18

do you see how in my example (in my first post) where I went from 2/3 to -3/2

did that all make sense?

Answer 19

I was thinking that Y=-1/2X

Answer 20

the perpendicular slope is -1/2, that's a good start

Answer 21

so m = -1/2

Answer 22

the point line g goes through is (2,2)

so this means that x = 2 and y = 2

Answer 23

but how do I figure this out IM not so good with all these formulas can you dumb this down a bit for me.

Answer 24

now we turn to y = mx+b and plug in m = -1/2, x = 2 and y = 2


y = mx + b

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

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

2 = (-1/2)*(2/1)+ b

2 = (-1*2)/(2*1)+ b

2 = -2/2 + b

2 = -1 + b

2 + 1 = b

3 = b

b = 3

Therefore, m = -1/2 and b = 3

So the equation of line g is

\[\large y = -\frac{1}{2}x + 3\]

Answer 25

let me know what you think

Answer 26

Im still trying to undersdand MX+B
i know that those numbers have a funtion and you need to know what those are to move on right?

Answer 27

m is the slope of the line

b is the y-intercept of the line

Answer 28

that is what my book says

Answer 29

x and y are variables

they can be any number

the value of y will depend on what x is

Answer 30

and you need to do some math to find the slope and I needed to know the other parts to do this problem right?

Answer 31

the usefulness of y = mx+b is that you can find the equation of any line if you know the slope and any point on the line

Answer 32

are you a teacher?

Answer 33

I'm a student learning to become one

so yes and no

Answer 34

and yes, you need to figure out the slope before you can move on

Answer 35

I think I gave that to you right, which I got 2 for that

Answer 36

how did you find out y is that one of the four numbers that you use to plot the line?

Answer 37

what do you mean?

Answer 38

yes the original slope (ie the slope of h) is 2

Answer 39

I am trying to understand the whole equation I hate just getting the answers to a problem and not know how to solve it you know, i was wondering what Y is and how do you get the numbers for all the letters in this math problem.

Answer 40

ive been on google all night looking up how to solve for all these math problems and have been comming up with the right answers but have been struggling to understand them.

Answer 41

y is a variable and it is not assigned a fixed value like m or b are

Answer 42

when you say y = 2x, you are saying "for each x you plug in , you double the value to get y"

so that means if you plug in x = 1, you get y = 2 (double 1 to get 2)

when you plug in x = 13, you get y = 26 (double 13 to get 26)

Answer 43

this produces a bunch of points, you plot these points, then draw a line through them to graph y = 2x

Answer 44

My problem is im trying to do these in my head I dont have a calculator or graphing paper :(

Answer 45

well if you can't do them in your head, use pencil and paper

Answer 46

you can use google as a calculator

ex: type in "2*3 + 10" into google without quotes and it will spit out the result like a calculator

Answer 47

i was trying to graph the lines to visualize them

Answer 48

and if you need a program to help you graph, I recommend geogebra

http://www.geogebra.org/cms/en/

Answer 49

to graph the lines, you just need two points

so one point on y = 2x is (1,2)

another point on y = 2x is (2,4)

plot the two points (1,2) and (2,4) and draw a straight line through them

this will give you the graph of y = 2x

Answer 50

here is the next part to the questions that you have helped me with,

If line F is parallel to the line H, and line F has Y-intercept 5, what is the equation of line F?

can you walk me through all the steps and ill write them down as we go i really want to lean this type of math.

Answer 51

im guessing it is using the answer to the last question that you helped with.

Answer 52

what is the slope of line h

Answer 53

yes it all builds up

Answer 54

ok let me see what I have for that. I got 2 for that.

Answer 55

so m = 2

Answer 56

ok got it.

Answer 57

the y-intercept is given to be 5, so this means b = 5

Answer 58

so we go from

y = mx+b

to

y = 2x + 5

Answer 59

that's the equation of line f

Answer 60

why is the slope 2? because parallel lines have equal slopes

Answer 61

slope of h is 2

line f is parallel to h

so the slope of line f is also 2

Answer 62

do you have a aol sceen name i could add you to my list to ask another question some time?

Answer 63

im still writing down your words for the problem right now.

Answer 64

I don't use AOL messenger, but I do use yahoo messenger

Answer 65

oh i dont have that installed now. but you can email me at doclovett@yahoo.com

Answer 66

So Y and B are the same as 5? is this correct.

Answer 67

b is 5, y is a variable

y is allowed to change

Answer 68

so y is an unknown

Answer 69

yes

Answer 70

it represents any number pretty much at this point

the same can be said for x

Answer 71

ok

Answer 72

damn now I have to deal with a triangle and COS and TAN

Answer 73

thanks for your help. I am trying to figure out angles with Sin A=15/17

Answer 74

check out this page

http://openstudy.com/updates/521ef027e4b0750826e0c91a

I think you (zombiebacon) and the user jaidyn206 are taking the same course. I could be wrong.

Answer 75

so you guys can set up a study session if that is true

Answer 76

yeah she is in my class im talking to her in aim she is ahead of me in the class on different questions.

Answer 77

I gotcha

Answer 78

what does sin A=15/17 mean

Answer 79

i just wasted a few min figuring out degrees in angles for nothing didn't I?

Answer 80

if you have a right triangle that looks like this

Answer 81

then the sine of the angle A is equal to the opposite side (15) over the hypotenuse 17

ie, sin(A) = 15/17

Answer 82

no I don't think you wasted your time

Answer 83

how do I draw a picture to show you

Answer 84

use the draw button below the text box

Answer 85

that works