Question

How do you multiply `sqrt(-9)sqrt(-63)`?

Answer 1

`=> sqrt 567`

Explanation:

`sqrt -9 * sqrt -63`

`=> sqrt (-9 * -63 ) = sqrt 567`

Answer 2

`-9sqrt7`

Explanation:

`"simplify each radical"`

`"noting that "sqrt(-1)=i`

`sqrt(-9)=sqrt9xxsqrt(-1)=3i`

`sqrt(-63)=sqrt9xxsqrt7xxsqrt(-1)=3sqrt7i`

`[i^2=(sqrt(-1))^2=-1]`

`3ixx3sqrt7i=9sqrt7xxi^2=-9sqrt7`