Question #87457

1 Answer
Jun 13, 2017

#2sqrt10i#

Explanation:

#sqrt(-40)# is a complex root.
Complex roots are roots of negative numbers.
#sqrt(-40)=sqrt(-1)*sqrt40#
#sqrt(-1)# is an imaginary number in maths (notated by #i#)
Therefore, #sqrt(-40)=sqrt40i=sqrt(4*10)i=2sqrt10i#