To find the square root of a negative number use the next:
![√(-1)=i](https://img.qammunity.org/2023/formulas/mathematics/high-school/vges45wsdlzv2kdiaeb5hg4ttr8y86n8cg.png)
For -6:
You can write -6 as the product of 6 and -1:
![√(\left(6\right)*\left(-1\right))](https://img.qammunity.org/2023/formulas/mathematics/college/dfnqk9nhgnmhds4ryuw1dmu2x12jurwuti.png)
The square root of a product is the same as the product of the square root if each of the factors:
![=√(6)*√(-1)](https://img.qammunity.org/2023/formulas/mathematics/college/2b96jnw78d3465xffctzm1xy3629cvxlnc.png)
As the square root of 6 is not a exact number (it has many decimals) you leave the square root of 6 as it is. The square root of -1 is i; then, the square root of -6 is:
![\begin{gathered} =√(6)*i \\ =√(6)i \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/9ikrujld9kpdct6k2wtjr90ze8tyadj8ys.png)
Then, the square root of -6 is: (√6)i