Question

How to find cube root by successive subtraction method and how to take out the numbers by which number has to be subtracted ??

Answer 1

Method of successive subtraction to find the cube root:

We Subtract the numbers 1, 7 ,19 ,37, 61, 91, 27 169........ Successively till we get zero.

The number of subtractions will give the cube root of the number.

The number 1, 7, 19, 37, 61, 91, 127, 169....... are obtained by putting n= 1,2,3...... in 1+n×(n-1)×3

For e.g:
Find the cube root of 125

125-1=124

124-7=117

1117- 19=98

98- 37=61

61-61=0

The number of subtractions to get zero is 5
³√125= 5
_____________________________Hope this will help you...

Answer 2

Answer: Find it with a formula = 1+n(n-1)×3. Or find it with a trick. Which is given below.

Step-by-step explanation:

Trick is,,, (you know that 1st no. of the successive substraction method is 1)

To find second no. Add 6 in it and then multiple of 6. See in applied trick

Applied trick--

First no. 1

Second no.= 1+6=7

Third no. = 7+12=19

Fourth no.=19+18=37

Fifth no.= 37+24=61.

.

.

. And so on.

Hope it helps you