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If the quadratic x^2+6mx+m has exactly one real root, find the positive value of m.

 Dec 25, 2018
 #1
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x^2 + 6mx + m  =  0

 

If this has one real root the discriminant  is  0

 

So...

 

(6m)^2 - 4m  =  0

36m^2 - 4m = 0

9m^2 - m  =  0            factor

 

m (9m - 1)  = 0

 

Setting each factor to 0 and solving for m produces

 

m =  0       or     m =  1/9

 

 

cool cool cool

 Dec 25, 2018

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