Question

How do you find all the real and complex roots of `x^2 - 20 = 0`?

Answer 1

roots are real `x = ±2sqrt5`
There are no complex roots

Explanation:

`x^2 - 20 = 0 rArr x^2 = 20 rArr x = ±sqrt20`

now`sqrt20 = sqrt(4 xx 5 ) = 2 sqrt5`