word problem

Question

The height in feet, h, reached by a softball after t seconds is given by the function
h(t) = −16t2 + 89t + 3.
During what time interval did the softball reach an altitude of at least 80 ft?

Answer 1

Solve the inequality -16t² + 89t + 3 ≥ 80 for t, and remember that since t is a unit of time, then t cannot be negative