Question

question 10 of 10
a complex number is a number of the form a + bi, where:

a. a is a real number and bi is an imaginary number.
b. a is an imaginary number and bi is a real number.
c. a and bi are real numbers.
d. a and bi are imaginary numbers.

Explanation:

A complex number is defined as \(a + bi\), where \(a\) and \(b\) are real numbers, and \(i=\sqrt{- 1}\) (the imaginary unit). So \(a\) is a real number (the real part), and \(bi\) (where \(b\) is real) is an imaginary number (the imaginary part). Option A matches this definition. Option B swaps real and imaginary, Option C says \(bi\) is real (which is false as \(i\) is imaginary), and Option D says both are imaginary (false as \(a\) is real).

Answer:

A. \(a\) is a real number and \(bi\) is an imaginary number.