SOLUTION: A golf ball is hit in the air. the path of the golf ball can be described by the equation h = 55t - 5t where h is the height of the ball in meters and t is the time after how many

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Question 255024: A golf ball is hit in the air. the path of the golf ball can be described by the equation h = 55t - 5t where h is the height of the ball in meters and t is the time after how many seconds will the ball be in 160 high
Found 2 solutions by Greenfinch, Alan3354:
Answer by Greenfinch(383) About Me  (Show Source):
You can put this solution on YOUR website!
I think one of these t should be squared. Until I know which one, I can't answer.

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
It should be 55t - 5t^2, and it's 160 meters high, not 160 high.
-5t^2 + 55t - 160 = 0
-t^2 + 11t - 32 = 0
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case -1x%5E2%2B11x%2B-32+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%2811%29%5E2-4%2A-1%2A-32=-7.

The discriminant -7 is less than zero. That means that there are no solutions among real numbers.

If you are a student of advanced school algebra and are aware about imaginary numbers, read on.


In the field of imaginary numbers, the square root of -7 is + or - sqrt%28+7%29+=+2.64575131106459.

The solution is , or
Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+-1%2Ax%5E2%2B11%2Ax%2B-32+%29

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It doesn't go that high.
The max height is 123.75 meters, at t = 5.5 seconds.