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A Review of Radicals

What about sqrt(-49)?

Can we find a number that goes in this?

( )^2 = ( )( ) = -49

Since these are the same number, we'd either have

( - )( - ) = + or ( + )( + ) = +

( )^2 = -49
That's why a square can't be negative!

In fact, this goes for ALL even roots.

4th root of -16 Can't do!

Since no number works in

( )^4 = -16

There'd be an even number of the guy multiplied together:

( )( )( )( ) = -16 ... ( - )( - )( - )( - ) = + or ( + )( + )( + )( + ) = +
                                                            This negative can't happen!