You need to evaluate the absolute value of the given complex number, using the following formula, such that:

`|z| = sqrt(x^2 + y^2)`

Identifying the real part x and the imaginary part y, yields:

`{(x = 1),(y = -2):}`

Reasoning by analogy, yields:

`|z| = sqrt(1^2 + (-2)^2)`

`|z| = sqrt(1 + 4)`

`|z| = sqrt 5`

**Hence, evaluating the absolute value of the given complex number, yields **`|z| = sqrt 5.`

**Further Reading**

## We’ll help your grades soar

Start your 48-hour free trial and unlock all the summaries, Q&A, and analyses you need to get better grades now.

- 30,000+ book summaries
- 20% study tools discount
- Ad-free content
- PDF downloads
- 300,000+ answers
- 5-star customer support

Already a member? Log in here.

Are you a teacher? Sign up now