Question

How to symplify this radical expression? -√49 (thats supposed to be a square root sign)

Answer 1

Well, what's the square root of 49? Is there any number you can think of that you can multiply by itself to get 49?

Answer 2

I know the square root of 49 is 7 I'm just confused about the negative sign

Answer 3

Do I have to use i

Answer 4

You only have to use i if the negative sign is inside the square root symbol

Answer 5

Nope, you only have to use i if the negative sign is inside the square root. Because if you think about it, (-2)^2 is 4 and 2^2 is 4, so you will never get a negative number if you multiply two negatives together. i=square root(-1)

Answer 6

so then what would I do is it was say \[\sqrt{-81}\]

Answer 7

\[\sqrt{-81}=\sqrt{81*-1}=9i\]

Answer 8

okay thanks