A ball is thrown in air and it's height, h(t) in feet, at any time, t in seconds, is represented by the equation h(t)=−4t2+16t. When is the ball higher than 12 feet off the ground?
+14913 A ball is thrown in air and it's height, h(t) in feet, at any time, t in seconds, is represented by the equation h(t)=−4t2+16t. When is the ball higher than 12 feet off the ground?
Ein Ball wird in die Luft geworfen und seine Höhe h (t) in Fuß zu jeder Zeit, t in Sekunden, wird durch die Gleichung h (t) = - 4t2 + 16t dargestellt. Wann ist der Ball höher als 12 Fuß über dem Boden?
Hello Guest!
\(h (t) = - 4t^2 + 16t=12\ feets\)
\(- 4t^2 + 16t-12=0\)
\(t= {-b \pm \sqrt{b^2-4ac} \over 2a}\)
\(t= = {-16 \pm \sqrt{(16)^2-4(-4)(-12)} \over 2(-12)}\)
\(t=\frac{-16\pm 8}{-24}\)
\( t_1=\frac{1}{3}\ second\\ t_2=1\ second\\\)
The ball is higher than 12 feet off the ground
between \( t_1=\frac{1}{3}\ second\) and \( t_2=1\ second\).
!
