Question

Can someone help me with number 8 plz

Answer 1

We have the following equation:
 h (t) = - 16t ^ 2 + 161t + 128
 We substitute the value of h (t) = 170:
 170 = -16t ^ 2 + 161t + 128
 We rewrite the equation:
 -16t ^ 2 + 161t + 128 - 170 = 0
 -16t ^ 2 + 161t - 42 = 0
 We look for the roots of the equation:
 t1 = (161/32) + root (23233) / 32
 t2 = (161/32) - root (23233) / 32
 Answer:
 The object is 170 feet off the ground at the following times:
 t1 = (161/32) + root (23233) / 32
 t2 = (161/32) - root (23233) / 32