- sqrt(1) - sqrt(-400) = -1 - 20i, where "i" is the imaginary unit.

- sqrt(1) - sqrt(-400) = -1 - 20i, where "i" is the imaginary unit.

- sqrt(1) - sqrt(-400) = -1 - 20i, where "i" is the imaginary unit.

- sqrt(1) - sqrt(-400) = -1 - 20i, where "i" is the imaginary unit.

The imaginary unit number is the square root of -1 and is denoted by i

definitely -1

A unit circle is in the coordinate plane where both axes are measured in real numbers. The imaginary circle is in the complex plane in which one axis (horizontal) measures the real component of a complex number and the other axis measures the imaginary component.

No, it is imaginary. Irrational numbers are a subset of real numbers Real numbers and imaginary numbers are sets without any overlap.