Question

Find the cube root of 0.000729 with solution​

Answer 1

Answer:

0.09

Explaination :

Take a number, 0.1*0.1

you get, 0.01

What you did is that you multiplied 1 * 1 and then counted the total number of digits are zero. In the above example 0.1*0.1 , there are 2 digits after decimal so you solved 1*1 and then simply placed point before two digits and got 0.01

Consider a square of a number,

2² = 4

0.2² = ?

For this, first find the square of 2 that is 4 and place a point after 0 as 0. , and then put 4 like 0. 4 and then the total number of digits after zero. (0.2)² = 0.2*0.2. Here we see that only 2 digits are there after zero. So in 0. 4 , place one zero between 0 and 4 and you get, 0.04. Now there are two digits after decimal and it will be the square of (0.2)².

Now this time we are going to do reverse. Take 0.04. Just reverse whatever you did previous. Find the square root of 4 and you get 2. Place 2 as 0. 2. In 0.04 there were 2 digits after decimal point, so there will be 2/2 = 1 digit after decimal point in its root. In 0.2, there is 1 digit after decimal point,

So √0.04 = 0.2

Now for the Question, I guess you have got the idea.

3√(0.000729 ) = ?

Find the cube root of 729 and you get 9. Number of digits after decimal point = 6. Divide it by 3 and you 2. So there will be 2 digits after decimal point in its cube root. Place 0 and 9 as 0. 9 . Now put 1 zero between them. 0.09 . Now there are two digits after decimal point and it will be cube root