Question

How to evaluate `(sqrt (-20))^2` step by step?

Answer 1

In General:
`sqrt(x)=x^(1/2)`
AND
`(x^a)^b=x^(a*b)`

`=>`

`(sqrt(-20))^2=`
`=((-20)^(1/2))^2=`
`=(-20)^(1/2*2)=`
`=(-20)^(2/2)=`
`=(-20)^(1)=`
`=-20`