Question 56231
The path traveled by a golf ball hit with a 9-iron can be modeled with the quadratic function, y = -0.042x(squared) + 5x, where x is the distance in yards from the point it was hit and y is the height of the golf ball in feet. Assume that the ground is level. 
a. Find the maximum height reached by the ball.
a=-0.42, b=5
max at x=-b/2a=-5/(2(-0.42))=5.95238....
y=14.881 ft.
Comment: It seems highly unlikely that this is the 
height.  The model is erroneous.


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b. How far from where it was hit does the ball hit the ground?
height = 0 when the ball hits the ground.
0=-0.42x^2+5x
x(-0.42x+5)=0
x=0 or x=11.95 yrds 
Comment: Another nonsensicle answer based on the nonsensicle
model you have posted.
Cheers,
Stan H.