1

For example in y=1/x, variable y and x are inversely proportional.

If y and x have a different relation than inversely proportional, but still y decreases as x increases and vice versa, how do you describe their relation? Thanks!

  • 1
    Drop the "proportional" and just refer to it as an inverse relationship.' – Jim Mar 6 '14 at 4:15
2

Inversely proportional doesn't only describe the direct 1/x case, but the general case where y decreases when x increases. So even if you had a formula like:

y = 12 + 57/(2x + 5)

or

y = 1/x^2

You would still describe the relationship between y and x as inversely proportional.

  • 1
    A mathematically proportional relationship requires that the change be related by a constant multiplier, not just moving in opposite or the same directions. – ColleenV parted ways Nov 6 '14 at 21:48
1

"Monotonically decreasing" describes a situation where (as x goes up) y either stays the same or goes down. For "continuous functions", this is the same as saying that dy/dx <= 0.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.