The function f(t) =-16t 2 + 248 models the height f(t) in feet of a stone t seconds after it is dropped from the edge of a vertical cliff. How long will it take the stone to hit the ground? Round to the nearest hundredth of a second.

9514 1404 393

  3.94 seconds

Step-by-step explanation:

You want the value of t when f(t) = 0.

  0 = -16t^2 +248

  t^2 = = 248/16 = 15.5

  t = √15.5 ≈ 3.94 . . . . . . seconds

It will take about 3.94 seconds for the stone to hit the ground.

hope this is what you were asking for!

step-by-step explanation:

m∠a is 90°

m∠b is 40°