What does variation mean in math terms?
There are different types of variation in math - direct
variation, inverse variation, and joint variation for a start.
Direct variation is just simply that x and y vary directly. What
this means is that they do the same thing - as x increases so does
y, or as x decreases so does the value of y.
In general the formula for direct variation is y=kx where k is
the constant of variation.
(For example we could have a direct variation equation such as
y=2x. The constant of variation is 2, which just means that as x
increases, y doubles that amount and thus also increases)
Inverse variation is when x and y do the opposite of each other.
So as x increases, y decreases or as x decreases the value of y
increases. One fun example of where this happens in real life is
with Ramen Noodles - the less money people make the more Ramen
Noodles they buy. We would say that people's income and the amount
of Ramen Noodles they buy vary inversely.
In general the formula for inverse variation is y = k/x where
again k is the constant of variation.
Joint variation is when you have three variables that are
related. The general formula for joint variation is y=kxz where z
is just a third variable and k is still the constant of
variation.