The equivalent expression is 3i.
What is an expression?
In mathematics, an expression or mathematical expression is a finite combination of symbols that is well-formed according to rules that depend on the context.
How to determine?
As we know,
When there is a minus in square root
Here, comes iota(i)
So,[tex]\sqrt{-9}=3i.[/tex]
The equivalent expression is 3i.
Learn more about expressions:
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