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Question 489790: My problem is: the square root of 1860 a^70 x^44
I worked it out and got the answer
2|a^35| x^22 sq root 465, but what I can't understand, is why is the "a" in absolute value and not the "x"? I was taught that if the square root is even and the exponent is even then use absolute value. Can you explain it to me?
Thanks so much!
Tracy
Answer by chessace(471)   (Show Source):
You can put this solution on YOUR website! I think you lesft out a "not" in "if exponent is even"; your answer shows "if exponent is odd".
Let's assume the orginal is positive, and you want to find a positive sqrt which can then be multiplied by -1 to get the other root if anyone cares.
So you want your answer to be >0 even if "a" and "x" are not:
Either/both of them <0 will not change the sign of the original.
Your answer has a^35 and x^22 in it.
If x<0, x^22 is still >0, so you can leave it alone.
If a<0 then so is a^35, which you are trying to avoid, so use ||.
Alternative to illustrate the difference:
|a| * a^34 * x^22 is always >0
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