Just so you know, it has to be written as a lowercase i to represent an imaginary number.
a) 2i
The square root of 4 is 2, the negative under the square root is what makes it imaginary
b) 2i times the square root of 3
c) 5 + (5i times the square root of 2)
d) 3 - (i times the square root of 2)
