Let (a,b)=1 and ab=c^2. Show that a and b are perfect squares.

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hi all

I need some help with this question

Let (a,b)=1 and ab=c^2. Show that a and b are perfect squares.

Thank you
 
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Look at the prime factorization of a, b and c.
 
It took me a little while to comprehend what you meant by (a, b) = 1, but I concluded that you mean that a and b are relatively prime, namely that the largest factor they both share is 1.

To get you thinking about this the right way, try a few examples by assigning different values to a and b to see how that affects their products. The values you choose for a and b should be relatively prime. Keep in mind that your examples won't constitute a proof; they just help you think about the problem, and might help you formulate a real proof.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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