Algebra

 

If s is a real number, then what is the smallest possible value of 2s^2 - 8s + 19 - 7s^2 - 8s + 20?   

 

Combine terms               –5s² – 16s + 39     

 

If you set this equal to y and graph it, you see that    

the curve is a parabola that opens downward.    

 

When a parabola opens upward, the smallest y-value is the vertex.   

 

When a parabola opens downward, there is no smallest value.    

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