Question

a projectile is fired straight up from ground level. after "t" seconds its height above the ground is "s" feet where s=16t^2+128t. the projectile will be at least 240 ft above the ground beginning at__ seconds and ending at__ seconds

Answer 1

I think for this given it's highest height of 240 ft, replace s with 240 and solve for t at the beginning, and then put 0 in for s to solve for t at the end. But not sure