Finding the period of a differential equation?

adl2114
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find the period of the solution to this differential equation:

2y'' + 4y' + y = 0

I used the complementary equation 2r^2 + 4r + 1 = 0 and then used the quadratic equation to factor that into 2 roots of -2 + 2^(1/2) and -2 - 2^(1/2) and I know that 2 real, distinct roots means there is no period but If the problem had been different how would I go about finding the period after determining the roots?
 
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Well, first, your roots are off by a scaling factor of 1/2. And assuming that both roots are imaginary, well, e^(ix) is periodic, but I'm not sure of the period...
 
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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