Question

My question

Answer 1

?

Answer 2

If \(x\ \propto \ y\) and \(y\ \propto \ \dfrac{1}{z}\), then which of the following is correct

\(1.)\ x\ \propto \ z \\
2.)\ x\ \propto \ \dfrac{1}{z}\)

Answer 3

what is the sign?it looks like infinity

Answer 4

directly proportional/ inversely proportional

Answer 5

I got 2

Answer 6

how

Answer 7

x(n) X(z) Let y(n) = x(-n)
∞ ∞ ∞
Then Y(z) = ∑ x(-n)z-n
= ∑ x(r) z+r
= ∑ x(r) (z-1 ) -1 = X (z-1 )
n = -∞ r = -∞ r = -∞

Answer 8

yeah that;s right

Answer 9

haha ...

Answer 10

?

Answer 11

Did I mess up?

Answer 12

i guess it doesn't need that kind of calculation or whatever :D

Answer 13

i understand nothing , i m confusede

Answer 14

;-;

Answer 15

Well thats my work

Answer 16

@sparrow2 did u understand his work, if yes, please pass it to me

Answer 17

using only words :D: if x increases then y increases... if y increases then z decreases so we have if x increasis then z deacreases which is in the second

Answer 18

I'm so sorry I couldn't explain better

Answer 19

but the answer given is the first one

Answer 20

oh then i don;t know

Answer 21

in this video the guy explains it , but i can't understand

https://www.youtube.com/watch?v=BM7L9dlbS6w

Answer 22

from 1;00

Answer 23

please dont mistake this post as any openstudy feedback and start unnecessary converstion

Answer 24

the answer is 2489

Answer 25

@jigglypuff314

Answer 26

i was thinking using the transitive property thingy

Answer 27

the only thing i guess is we don't know if the operation has that property

Answer 28

do we know anything about that operation?

Answer 29

oh watching the video

Answer 30

ok so that one symbol means directly proportional to...
doesn't this means we can write the equations
x=ky and y=a/z
where k and a are constants
so replacing first y with a/z we obtain
x=k(a/z)
or
x=L/z
So x is inversely proportion to z

Answer 31

but you said and the video says that is incorrect

Answer 32

I guess the directly proportional thing doesn't mean what it used to mean in algebra

Answer 33

which answer is correct according to u

Answer 34

the one that is incorrect according to the video
but I haven't watched the whole video just to the part where he says the one I chose is incorrect

Answer 35

u mean \(x \propto \dfrac1z\) this is correct ?

Answer 36

yep did you understand my reasoning above?
like I read it as this we are given
x=ky and y=a/z

then this means x=k(a/z)=ka/z=L/z

so given x=ky and y=a/z then x=L/z

Answer 37

yea i got ur reasoning

Answer 38

u use substitution

Answer 39

yes

Answer 40

thnks

Answer 41

he continues to talk about x directly prop to y and y directly prop to 1/z
I don't get how x/(y*z) is a constant
from this

Answer 42

Thats what I said at the beginning @mathmath333 :P

Answer 43

if x/y is a constant and yz is a constant
then I can say
\[\frac{\frac{x}{y}}{yz} \text{ is a constant } \text{ or that } \frac{yz}{\frac{x}{y}} \text{ is a constant } \\ \text{ simplifying } \\ \frac{x}{y^2 z} \text{ and } \frac{y^2 z}{x} \text{ are constants }\]

Answer 44

http://www.themathpage.com/alg/variation.htm
this site agrees with us
it says varies directly is a transitive relation