How do you use imaginary number in a scientific calculator?

Answer 1

Each calculator has its own nomenclature for working with imaginary and complex numbers. Many scientific calculators allow you to just type -1 and hit the square root button and it will give you something like (0,1) or (1,∠90°). In the first example, the first number {the 0} represents the real part, and the second number {the 1} represents the imaginary part. This is what happens on the HP-48 and HP-50 in Rectangular mode. In the second example, the calculator is in Polar mode (degrees), rather than Rectangular. So the first number {1} is the magnitude, and the second {90°} is the angle, measured in a counterclockwise direction from the positive real axis. 90° points straight up and is purely imaginary.

If my calculator was in radians mode, rather than degrees, then it would show (1,∠1.57) 1.57 radians is pi/2 (to 2 decimal places), which is the same angle as 90°.

An earlier calculator that I had, you first had to put the calculator in complex mode, then you had to push an extra button to view the imaginary part of the answer.