Question

How do you simplify `sqrt(16-x^2)`?

Answer 1

You cannot really simplify this, but you way want to rewrite.

Explanation:

Since `16-x^2=(4-x)(4+x)` you can write:

`=sqrt((4-x)(4+x))` or:

`=sqrt(4-x)*sqrt(4+x)`

This will only work if `-4<=x<=+4`, otherwise `16-x^2` will be negative = not allowed.