Question

Which expression is equivalent to square root of -80

Answer 1

i4 squareroot 5 is the answer

Answer 2

 hello : 
in : C     let :    √(-80)= z
    z² = - 80 .... (1) 
 but : i² = -1   and : √(80) = 4√5
(1) equivalent :  z² = (4√5 i )²
conclusion : z = 4√5 i   or  z = - 4√5 i