how can i evalute? one problem

Question

1. negative square root of 25

Answer 1

Your statement is equivalent of

 

Negative square root of 25= - ( √25) = -5

 

Square root of ( negative 25) = √-25 =  √25 .√-1 = 5i

Answer 2

√-25 can be written as 

 

 √-1 * √25

 

Square root of -1 is 'i' - imaginary unit (http://en.wikipedia.org/wiki/Complex_number)

 

 i * 5

 

So square root of -25 is

 

5i