Question

Help meh. EXPLANATION REQUIRED.

Answer 1

with?

Answer 2

a direct variation between u and v looks like this
u=kv where k is a constant. Though you can do division of k or v and make the relationship look a little differently... But basically if you are able to multiply by a constant to either u or v and get v or u respectively then it is a direct variation.

Answer 3

^ Confusing

Answer 4

Wait, how do you divide k and u?

Answer 5

*v

Answer 6

u=kv

if you divide both sides by k you get u/k=v

if you divide both sides by v you get u/v=k

Answer 7

instead of u/k=v

it could be cu=v where c is the new constant

you could also choose divide both sides by c giving you u=v/c

or if you choose to divide both sides by u giving you c=v/u

Answer 8

I dont get it.

Answer 9

So summary equations looking like the following thing direct variation between u and v:
u=kv
u/k=v
u/v=k
v=cu
u=v/c
c=v/u

notice the only operations here are multiplication and division

Answer 10

does v=1/u+6 looks like any of the forms I mentioned above?

Answer 11

Urrrrmmm.... Idk. Yesss?

Answer 12

so you see a plus sign in one of the forms I mentioned?

Answer 13

No.

Answer 14

which one has a plus sign?

Answer 15

Ok.

Answer 16

what about v/u=9

Answer 17

so many ppl in k12

Answer 18

Yes, Same as v/u=k, right?

Answer 19

u=kv
u/k=v
u/v=k
v=cu
u=v/c
c=v/u

right that one looks like the last one I wrote

Answer 20

what about 0.5(1/u)=v
notice you can also write this as 0.5/u=v

Answer 21

No. None simular.

Answer 22

right that is actually an indirect variation

Answer 23

oh, ok.

Answer 24

and last one

Answer 25

Last one?

Answer 26

yes what do you think about the last one

Answer 27

Oh, 3.5u= v? Yes, I think its simular to the first one.....

Answer 28

the first one being v=1/u+6
how?

Answer 29

summary: it is a direct variation between u and v if you can express the equation in the form u=kv where k is a constant.

We cannot do that with v=1/u+6 <---notice the addition
v/u=9 can be written as v=9u or 1/9*v=u <--- this is a direct variation because it is in the form u=kv
0.5(1/u)=v is a indirect variation because it is in the form v=k/u
v=3.5u or also known as u=v/3.5 or u=(1/3.5)v is a direct variation because it is in the form u=kv


I took u=kv and wrote it in all the forms I can think of:
u=kv
u/k=v
u/v=k
v=cu
u=v/c
c=v/u
to make it easier for you

A definitely doesn't have any of those forms
B is in that last form.
C is in none of those forms.
D is in the 4th form there.

Answer 30

The formula for direct variation is y = kx, where k is the constant of variation.

Answer 31

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&ved=0ahUKEwiAjvuz-ujKAhUU0mMKHcS_D8wQjRwIBw&url=http%3A%2F%2Fwww.slideshare.net%2FTeach5ch%2Fdirect-variation-6039625&psig=AFQjCNEB7qHTitXgvVVZnlnG8Ut0cmXVJw&ust=1455047976687170

Answer 32

hopefully that helps @Thadds2003