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Find all nonzero constants a such that

 

ax^2-5x+9=0

has only one distinct root.

 Nov 8, 2017
 #1
avatar+98196 
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If ax^2-5x+9=0  has only one root, the discriminant must = 0

 

Therefore

 

(-5)^2 - 4 (a)(9)  = 0

 

25  = 36a

 

a = 25/36

 

Here's a graph proving this :  https://www.desmos.com/calculator/puzyhvuy39

 

 

cool cool cool

 Nov 8, 2017

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