Question

What does it mean when something is inversely proportional or Directly proportional?
a proper explanation please​

Answer 1

Answer:

Two variables a and b are said to be inversely proportional if; a∝1/b. In this case, an increase in variable b causes a reduction in the value of variable a. Similarly, a decrease in variable b causes an increment in the value of variable.

Answer 2

Man, you've to read the whole answer now. :( But you may be benefitted for sure.

DIRECT PROPORTION:

When any quantity is directly proportional with any other quantity, increase of the quantity with a factor, say a, will also imply that the other quantity is also increasing by the same factor, i.e., a.

I mean, say a man walks with a speed of v m/s randomly (without any aim) and the distance covered will be, say 'x' m.

So, if the man increases the speed of his walk by a 6 times, then he will also cover a distance which is 6 times the distance he covered earlier.

Now, it is called as direct variation. It is mathematically represented as:-

$x \propto y$ if x,y are some quantity.

INDIRECT PROPORTION:

When any quantity is indirectly proportional with any other quantity, increase of a quantity of a factor, say a, will lead to decrease of the other quantity by a factor of a.

Let us assume that, a man, with his bike, is late to his office and wants to reach his destination in quickly. That is, he will double the speed of his vehicle to reach quickly.

We observed that, here the rider increased its speed which led to reach his place in half of the time he'd reach with his normal speed.

Now, if he increased speed by 6 times, then time taked will be decreased by a factor of 6. (t′ = 1/6 t.)

So, it is called inderect proportion. It is shown as:

$x \propto \dfrac{1}{y}$ where,x,y are some quantity.