Question

Real and Imaginary Parts Find the real and imaginary parts of the complex number.

$2-\sqrt{-5}$

Short answer

The real part is 2 and the imaginary part is $-\sqrt{5}$.

Step-by-step solution

Step 1. Concept of complex number.

A complex number is of the form $a+bi$. Where a and b are some real numbers and i is the imaginary number.

The number a is known as the real part of the complex number and b is known as imaginary part of the complex number.

Step 2. Example for complex number.

In the complex number $2+5i$, the real part is 2 and the complex part is 5.

The imaginary number i is defined as the square root of negative one. That is, $i=\sqrt{-1}$.

Step 3. Find real and imaginary parts.

To find the real and imaginary parts in the complex number $2-\sqrt{-5}$, first rewrite it in standard form as shown below

$$\begin{gathered} 2-\sqrt{-5}=2-\sqrt{5}\cdot \sqrt{-1} \\ =2-\sqrt{5}\cdot i \\ =2-\sqrt{5}i \end{gathered}$$

Observe that the number 2 is separate without imaginary number i with it, so 2 is the real part.

And the number$-\sqrt{5}$ is associated with the imaginary number i so it is the imaginary part of the complex number.

Thus, the real part of the given complex number is 2 and the complex part is $-\sqrt{5}$.