Question

How do you find the absolute value of `-9+6i`?

Answer 1

`sqrt117`

Explanation:

Given a complex number `z=x+yi` then using Pythagoras' theorem, it's magnitude is.

`color(red)(bar(ul(|color(white)(a/a)color(black)(|z|=|x+yi|=sqrt(x^2+y^2))color(white)(a/a)|)))`

here x = - 9 and y = 6

`rArrsqrt((-9)^2+6^2)=sqrt(81+36)=sqrt117" absolute value"`