Question

Please help me!!! I will fan and medal!

Answer 1

@imqwerty please help no one will answer

Answer 2

hello :)

Answer 3

hi

Answer 4

direct variation between \(x\) and \(y\) means that the equation must be of this form-> \(\large y=kx\)
where \(k\) maybe any number :)

Answer 5

try to answer it now :)

Answer 6

so it has to be either A or D since those arent in that format?

Answer 7

Why do you think that D is not in that format?

Answer 8

Because it is dividing?

Answer 9

okay lets compare the standard form with the option D

Standard form-> \(\color{violet}{\large y=kx}\)
Option D-----> \(\color{violet}{\large y= \Large\frac{x}{9}}\) or we can say-> \(\color{violet}{\large y= \Large\frac{1}{9}\times x }\)

try figuring out what will be our \(k|) in option D

Answer 10

the k is 1/9?

Answer 11

yes :)

now read that definition of direct variation i wrote in beginning
it says k can be any number so will option D be direct or not

Answer 12

direct

Answer 13

:) and we need to find the option which does not shows direct variation
what do u think it will be

Answer 14

A

Answer 15

bingo correct :D

Answer 16

Awesome thank you.
I have a few more however.
Do you have time? :)

Answer 17

yeah i hav some time :)

Answer 18

I think A and B

Answer 19

i forgot to add one thing in the definition
it is-> that \(k\) must be positive number

if \(k\) is negative then its not a direct variation

Answer 20

Oh okay that helps a lot

Answer 21

and in a direct variation -> as we increase the value of \(x\) the value of \(y\) will also increase simultaneously

Answer 22

okay. so i think it cant be B or D because they are both negative, right?

Answer 23

@imqwerty ?

Answer 24

sry it was lagging

Answer 25

okay heres a more refined definition of direct variation->

direct variation between \(x\) and \(y\) is of the form->
\(\large y=kx+c\)

\(c\)--> any constant number [can be positive or negative]
\(k\)--> any constant number[can only be positive]

:) if the above rules aren't satisfied then relation is not direct relationship

Answer 26

now try to figure the options out :)

Answer 27

So A,C, and D?

Answer 28

c can also be 0

Answer 29

how can it be 0?

Answer 30

okay :)
we know that basically direct variation means that as we increase \(x\) , \(y\) must also increase
agreed?

Answer 31

yeah

Answer 32

now we gotta prove that \(y=kx+0\) is a direct variation and we know that \(k\) is some positive number

Answer 33

do you agree that \(y=kx\) will be a line?

Answer 34

yes

Answer 35

can you tell what will be the slope of this line

Answer 36

not really, i dont know how to find slope without points

Answer 37

all i know is that it has to be a positive slope

Answer 38

why did you say that? :)

Answer 39

because a direct slope has to be positive or it wont be direct

Answer 40

:) why did you say it to be direct

Answer 41

im confused now

Answer 42

okay :) so you know that if \(y=kx\) has a direct slope then the slope will be positive right?

Answer 43

yep

Answer 44

are you familiar with slope intercept form of line? :)

Answer 45

a little bit

Answer 46

okay this is it->
\(y=mx+c\)

where \(m\)-->slope of line
\(c\)-->y intercept of line

Answer 47

now try to find the slope of \(y=kx\) by comparing it with the slope intercept form

Answer 48

c=0 because it intercepts at (0,0) right

Answer 49

yes correct :)

Answer 50

y=2x+0?

Answer 51

why did u put that 2 there?
you just have to find the value of \(m\) [slope] in this equation-> \(y=kx\) :)

Answer 52

wait, can i just put in k as m?

Answer 53

yes :)
so your slope becomes \(k\)

Answer 54

and you know that \(k\) is positive
so our slope is positive
what will you say about the equation :) direct or indirect

Answer 55

direct

Answer 56

so now we can say that \(c\) = 0
can work :) for \(y=kx+c\)
where \(k\) is positive constant

Answer 57

ok

Answer 58

okay so now use that definition above to figure out direct and indirect relation ships

Answer 59

for the answers?

Answer 60

yes try to find the answer now :)

Answer 61

I believe it is A and D, and maybe C.

Answer 62

correct!!! :D

Answer 63

Okay, I totally get this now. Thank you

Answer 64

np :)

Answer 65

You rock, mainly because we were here a long time but you kept helping, and I don't see those types of people on here that often. :)

Answer 66

you rock as well (B

Answer 67

bye

Answer 68

c ya :)

Answer 69

mhm, good job qwertay :3

Answer 70

Somehow it was A and B????