Find all nonzero constants a such that
ax^2-5x+9=0 has only one distinct root.
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
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