can someone pls pls explain to me this law ion the most simplest of words, with egs, pls dont copy and paste the online definitions, ive seen them all, i just need to understand it from someone whose understood it very nicely already , pls, with examples!

rosala
Jul 9, 2017

#1**+3 **

Hi, rosala.....good to see you.....!!!

Reciprocal propotions have the property that, as one variable increases, the other decreases. We also usually have something known as the "proportionality constant " to deal with. The way these problems usually work is that they will tell you the initial value of the two variables. This will usually lead us to solve for the proportionality constant. Then, they will ask you for the value of one of the variables, given the value of the other one.....Here's an example.....

Let's suppose that x = 6 when y = 3......so we have this form....

y = k / x where "k" is the proportionality constant that we need to find

So....substituting for x and y, we have that

3 = k / 6 multiply both sides by 6

18 = k so......this is the proportionality constant

Now......find y when x = 36 ......so we have

y = 18 / 36

y = 1/2

Did you happen to notice that when x = 6 , y = 3 ??

But as x increased to 36, y decreased to 1/2 ......this is what should happen in a reciprocal proportion....one variable increases and the other decreases

We can have it the other way, too.....let y = 36 and find x .....so we have

36 = 18 / x multiply both sides by x and divide both sides by 36

x = 18 / 36 = 1 / 2

So this time....when y increased from 3 to 36, x decreased from 6 to 1/2 !!!!

There may be other types of these problems, but this is the basic gist of reciprocal proportions.....hope that helped.....!!!!

CPhill
Jul 9, 2017