Question

Which of the following is a complex number?2+ 34 9i

Answer 1

Answer:

Option 3 -  $4+9i$                          

Step-by-step explanation:

Given : Options in the figure.

To find : Which of the following is a complex number?

Solution :

Complex number is defined as the number which contains real number along with imaginary number.

The complex number is in the form of a+ib.

Now, we determine one by one.

Option 1 - -7

-7 is the real number not complex.

Option 2 - $2+\sqrt{3}$

$2+\sqrt{3}$ is the real number not complex.

Option 3 - $4+9i$

$4+9i$ is in the form a+ib so it is a complex number.

Option 4 - $\pi$

$\pi$ is the real number not complex.

Therefore, Only option 3 is the complex number.

Answer 2

4+9i, since i is a complex number which is the square root of 1. It is the only solution with i in it.