math
posted by manda on .
A cannonball is fired across a field. Its height above the ground after t seconds is given by 16t^2+104. How long does it take for the ball to reach its maximum height of 169 feet?

169 = 16t^2 + 104
16t^2 = 65
no solution,
it will never reach 169 ft, the maximum height is 104 ft when t = appr 2.5 seconds 
If 16t^2+104 mean :
 16 t ^ 2 + 104 t
then :
in google type :
quadratic equation online
Wfen you see list of results click on :
Free Online Quadratic Equation Solver: Solve by Quadratic Formula
Select one of method.
Then in rectangle type :
 16 t ^ 2 + 104 t = 169
and click option : solve it !
You will see solutions step  by  step
In this case solution are :
t = 13 / 4 sec = 3.25 sec