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Let f(x) = x^3 + bx + c, where b and c are integers.  If f(\sqrt{5}) = 0, determine b + c.

 Feb 21, 2025
 #1
avatar+130466 
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f(sqrt 5)  =  0

 

So

 

(sqrt 5)^3  + b(sqrt 5) + c =  0

 

5sqrt 5  + bsqrt (5)  + c   = 0

 

One  possibility

 

b = -5     c = 0

 

b + c  =  -5

 

 

cool cool cool

 Feb 21, 2025

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