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811 LearnersLast updated on August 5, 2025

The cube root of 9 is 2.08008382305. The cube root of 9 is expressed as ∛9 in radical form, where the “∛" sign is called the “radical” sign. In exponential form, it is written as (9)⅓. If “m” is the cube root of 9, then, m3=9. Let us find the value of “m”.
The Prime Factorization of 9 is 3×3, so, the cube root of 9 is expressed as ∛9 as its simplest radical form. We can find the cube root of 9 through another method, named as, Halley’s Method. Let us see how it finds the result.
Now, what is Halley’s Method? It is an iterative method for finding cube roots of a given number N, such that, x3=N, where this method approximates the value of “x”.
Formula is ∛a≅ x((x3+2a) / (2x3+a)), where
a=given number whose cube root you are going to find
x=integer guess for the cubic root
Let us apply Halley’s method on the given number 9.
Step 1: Let a=9. Let us take x as 2, since, 23=8 is the nearest perfect cube which is less than 9.
Step 2: Apply the formula. ∛9≅ 2((23+2×9) / (2(2)3+9)) = 2.08
Hence, 2.08 is the approximate cubic root of 9.


below given some common mistakes and how to avoide them:
Find ∛64/ ∛9
∛64/ ∛9
= 4 / 2.08
=1.923
Answer: 1.923
We know that the cubic root of 64 is 4, hence dividing 4 by ∛9.
If y = ∛9, find y³.
y=∛9
⇒ y3= (∛9)3
⇒ y3= 9
Answer: 9
(∛9)3=(91/3)3=9. Using this, we found the value of y3.
Subtract ∛9 - ∛8
∛9-∛8
= 2.08–2
= 0.08
Answer: 0.08
We know that the cubic root of 8 is 2, hence subtracting ∛8 from ∛9.
What is ∛(9⁶) ?
∛(96)
= ((9)6))1/3
=( 9)2
= 81
Answer: 81
We solved and simplified the exponent part first using the fact that, ∛9=(9)⅓, then solved.
Find ∛(9+18).
∛(9+18)
= ∛27
=3
Answer: 3
Simplified the expression, and found out the cubic root of the result.

Jaskaran Singh Saluja is a math wizard with nearly three years of experience as a math teacher. His expertise is in algebra, so he can make algebra classes interesting by turning tricky equations into simple puzzles.
: He loves to play the quiz with kids through algebra to make kids love it.






