What does it mean if something is "directly" or "inversely" related to something, also as in a graph?

Answer 1

If one thing is directly related to another, then when one of them gets larger the other will also get larger. In an inverse relationship, as one gets larger, the other gets smaller.

In graphs, for a direct relationship, the line will go upward, and for an inverse relationship, it will go downward.

Answer 2

Directly related - e.g. F=ma or force is directly related to mass times acceleration i.e. if either mass or acceleration is increased then Force increases (or decreases if m or a decrease). So as one increase so does the other (directly related).

Inversely related - e.g. F=G(m1m2)/r^2 (^2=squared) i.e. Force is indirectly related to the square of the distance between two masses. Or in English ... the farther apart two masses are the LESS the force of attraction between them. So as one increases the other decreases (inversely related).

Answer 3

Directly means that as one variable changes some other variable changes in the same way. So, if "y" increases and "x" varies directly as "y", then "x" increases, too.

Inversely, has the opposite meaning. If "y" goes up, and "x" varies inversely as "y", then "x" decreases.

So, in this equation y = 5x + 7, if y were to increase then x will have to increase too. It varies directly.

In this equation y = 1/3x if y gets bigger, the because x is in the denominator of a fraction, x will have to get smaller. It varies inversely.

HTH

Charles

Answer 4

if two quantities are directly related the increase in one will lead Tao corresponding increase in the other.
while if they are inversely related the increase in one will lead to a corresponding decrease in the other