Question

Which of the following is a complex number?

-7
2 + StartRoot 3 EndRoot
4 + 9i
Pi

Answer 1

4 +9i

Explanation:

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Answer 2

4 + 9i

Explanation:

a complex number by definition must have a real and imaginary components

imaginary components are denoted by the letter i, where i = √(-1)

the only choice with a real and imaginary components is 4 + 9i