Lesson: Fractional Exponents

Comment on Fractional Exponents

If you have the square root of (-5)^2, when applying the rules this should be [(-5)^2]^(1/2) which equals -5 when applying the rules for a power raised to a power and thus multiplying 2 and 1/2. But this is not the correct answer since the square root of (-5)^2 is obviously 5. Why are the rules not working here?
greenlight-admin's picture

Great question!

It comes down to the square root notation.

The notation tells us to take the POSITIVE root of a number. So, even though a number like 9 has two square roots (3 and -3), the square root NOTATION tells us to use only the positive root.

Does that help?

Nice, this is the exact question I had a few videos ago. Thanks Brent!

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