What is the square root of -72?

1 Answer
Rafael
Sep 21, 2015

#=6isqrt2#

Explanation:

-72 doesn't actually have a real square root, but it does have an imaginary one.

#sqrt(-72)#
#=sqrt(-1*8*9)#
#=sqrt(-1*2^2*2*3^2)#
#=(2*3)sqrt(-1*2)#
#=6sqrt(-1*2)#

We will be able to bring out -1, by denoting it as #i#.

#=6sqrt(-1*2)#
#=6isqrt2#
=

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