Question

does the equation y=3/x represent a direct variation?

Answer 1

what do you think?

Answer 2

i dont think it does

Answer 3

I'll give you an example of how to determine whether the equation has a direct variation or not, OK?

Answer 4

okay

Answer 5

y=4x+2

if you want to check this make a table of x & y values.

Answer 6

plug in 1, 2 and 3 for x, what do you get for y?

x y

1 6
2 10
3 14

Answer 7

so its true?

Answer 8

so the in the first x and y values x is 6 times less than y
in the second x and y values x is less 5 times less than y
in the third x and y values x is 14/3 times less than y

since the differences are different from each other, therefore the variation is Indirect.

See

Answer 9

you can usually determine this right away, if you see an equation with the y intercept, then you can say that it is indirect and in 100% cases you will be correct.

Answer 10

so this one would be indirect?

Answer 11

@meg_72, so what do you think about your example now?

Answer 12

My example is indirect, right!
What about your, why?

Answer 13

y varies with x means y= kx.
y varies inversely with x means y=k/x
k is a constant which means the value doesn't change.
Which one does your equation fit? Why? What is k?
Good luck!

Answer 14

so mine would be false. right?

Answer 15

varies inversely with x doesn't mean indirectly.

Answer 16

(correction)
doesn't necessarily mean indirectly

Answer 17

Actually it does @SolomonZelman. Both terms mean the same. And @meg_72 correct! Do you know what your constant k is equal to?

Inversely is actually the correct term; indirectly is used and has become a second conventional use .

Answer 18

Direct proportion: x increases y also increases as in y = kx
Indirect / Inverse proportion: x increases y decreases as in y = k / x

Answer 19

thank yall!