Problem : Express using the imaginary unit ı.

= 5ı.

Problem : Is 3 a complex number?

Yes. In standard form, it is written 3 + 0ı. Every real number is a complex number in which the imaginary part equals zero.

Problem : Rewrite the complex number +3ı4 in standard form z = a + bı and find a and b.

+3ı4 = 6ı +3 = 3 + 6ı. a = 3, and b = 6.

Problem : What is ı618?

ı618 = (ı4)154ƒı2 = - 1.

Problem : When the complex number z = - 2 + 3ı is plotted in the complex plane, in which quadrant is it?

Quadrant II.