Question 368989
h(t)=t^2-8.9t+14
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We know it is a "quadratic" because it is in the form of:
Ax^2 + Bx + C
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Looking at the coefficient associated with the t^2 term, since it is positive (happy face) the parabola opens upwards.  The vertex will give you the minimum.
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After how many seconds does the ball reach its minimum height? 
t = -b/(2a)
t = -(-8.9)/(2*1)
t = (8.9)/2
t = 4.45 secs
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What is that minimum height?
Plug the value above back into:
h(t)=t^2-8.9t+14
h(4.45)=4.45^2-8.9(4.45)+14
h(4.45)= -5.80 meters