Amir stands on a balcony and throws a ball to his dog, who is at ground level.
The ball's height (in meters above the ground), x seconds after Amir threw it, is modeled by:
How many seconds after being thrown will the ball reach its maximum height?
h(x) = - ( x+ 1) ( x - 7) simpliy
- (x^2 - 6x - 7) =
-x^2 + 6x + 7
In the form -x^2 + bx + c the number of seconds to reach ax height is given by :
-b / (2 * -1) ...so we have
-6 / ( 2 * -1) = - 6 / -2 = 3 seconds
This graph confirms this : https://www.desmos.com/calculator/x2ghsrm5tb