SOLUTION: how to simplify sqrt (12ab^3c^2)

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Question 447774: how to simplify sqrt (12ab^3c^2)
Found 2 solutions by mananth, ikleyn:
Answer by mananth(16949) About Me  (Show Source):
Answer by ikleyn(53570) About Me  (Show Source):
You can put this solution on YOUR website!
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how to simplify sqrt (12ab^3c^2)
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        The answer   2bc%2Asqrt%283ab%29   in the post by @mananth is  highlight%28highlight%28INCORRECT%29%29.

        The correct answer is   2%2Aabs%28b%29%2Aabs%28c%29%2Asqrt%283%2Aa%2Ab%29.


                                E x p l a n a t i o n


In problems of this kind, we assume that the variables are real numbers and the expression under the square root
is non-negative.


We should understand that c^2 is necessary (always) non-negative, but 'c' itself can be negative.


We also should understand that  ' b '  can be negative (together with b^3), but the product ' a*b^3 '  is necessary non-negative,
same as the product  ' ab '.


In the problems of this kind, it is also assumed that the value of the square root itself is also non-negative.


Therefore, when ' b^2 ' goes out the square root, it comes to outside as |b|, the absolute value of  ' b '.


Similarly, when ' c^2 ' goes out the square root, it comes to outside as |c|, the absolute value of  ' c '.


Therefore, the final formula in the answer is as it is shown in my post at the beginning.

Solved correctly and explained completely.