<PRE><B>Question 20119</B>
SEE THE FOLLOWING EXAMPLE   TO KNOW 



Is the square root of 9 equal to -3i? 
1 solutions

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Answer 9707 by venugopalramana(356)   on 2005-11-19 00:41:47 (Show Source): 

NO NO &gt;&gt;&gt;
-3i*-3i=+9*(i*i)=9*(-1)=-9
square root of a negative number only gives raise to complex numbers involving i..square root of a positive number is always real and does not involve complex or imaginary number i
so square root of +9 could be +3 or -3 
where as square root of -9 is +3i or -3i...i being defined with the property i*i=-1...which as you can see from above is an imaginary number

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