Question

At the start of a basketball game, the referee tosses a ball into the air for the jump ball. The equation that models the height of the ball is h(t) = -16t2 + 30t + 8. During what time interval is the height of the ball above 10 feet? (Round your answer to the nearest tenth of a second.)
a) Between 1.1 and 1.6 seconds
b) Between 0.1 and 1.8 seconds
c) Between 0.3 and 2.1 seconds

Answer 1

plug in 10 for h(t), then use the quadratic formula to solve for t.

Answer 2

\[10= -16t^{2} +30t+8\]\[0= -16t^{2} +30t-2\]do the quadratic formula on this, and you get the intervals.

Answer 3

\[-16t^2 + 30t + 8>10\]
\[-16t^2+30t-2>0\] solve
\[16t^2-30t+2<0\] get
\[0.0692223<t<1.80578\]