How to get square-root of negative number, e.g., sqrt(-3)?

Question

Given x<--3, I tried to get its square root (I know it should be an imaginary number), but it seems not working:

> sqrt(x)
[1] NaN
Warning message:
In sqrt(x) : NaNs produced

Is there any way to make it fly? Thanks!

Answer 1

You should use as.complex

> sqrt(as.complex(x))
[1] 0+1.732051i