Which of these is a complex number?

Question

asked Jan 7, 2020 171k views

2 Answers

Jeremy Haberman · Answer 1 · 2020-01-07T20:23:10+0000

Option: A is the correct answer.

The one which is a complex number is:

A.
$(8)/(3)+\sqrt{-(7)/(3)}$

We know that the complex number is one which is expressed in the form of :

a+ib

where a and b belongs to the set of real numbers.

and i is known as a imaginary number which is represented by:

i=√(-1)

A)

$(8)/(3)+\sqrt{-(7)/(3)}$

This could also be written in the form of:

$(8)/(3)+\sqrt{(7)/(3)* -1}\\\\i.e.\\\\=(8)/(3)+\sqrt{(7)/(3)}\cdot √(-1)\\\\i.e.\\\\=(8)/(3)+i\cdot \sqrt{(7)/(3)}$

Hence, the number is in the form of:

a+ib

where

a=(8)/(3) which is a rational number and hence belong to real number

and

$b=\sqrt{(7)/(3)}$ which is a irrational number and hence belong to a real number.

Patrick McGloin · Answer 2 · 2020-01-13T17:23:16+0000

Answer:

Option A is correct.

Explanation:

A complex number is that which has imaginary number i.e i in it.

We know √-1 = i

So, any term containing √-1 can be complex number.

In our question option A is only number having √-1 so, Option A i.e

$(2)/(3) + \sqrt{-(7)/(3) }$ is complex number.