Think of a number that is - 2197 when it is multiplied by itself three times.
- 13
Practice makes perfect
The cube root of a number a is another number b if b multiplied by itself three times is a. This means that if b is the cube root of a, then b raised to the third power results in a. Let's see some examples of this.
sqrt(a)= b
because b^3= a [0.8em]
c|c
sqrt(- 8)= - 2 & sqrt(27)= 3
because( - 2)^3= - 8 & because 3^3= 27
We will now find the cube root of - 2197. We need to think of a number that is - 2197 when it is multiplied by itself three times.
?^3= - 2197
We see that - 13 raised to the third power is - 2197, so the number we are looking for is - 13.
