Here's the thing. a tennis ball is dropped from the top of a tall building. The ball's height y, in meters, x seconds after it is released is y= - 4.9^2+200
+37170 OK...then it SHOULD read something like y = -4.9 t^2 +200 t=x
-4.9(3)^2 +200 = 155.9
=
Then it says when is the ball dropped 30 meters above the ground? & when does the ball hit the ground?
+37170 y = 30 = -4.9 t^2 + 200
-170 = -4.9 t^2
170/4.9 = t^2
t = 5.89 sec when the ball is still 30 meters above the ground.
When the ball HITS the ground, y = 0 0 = -4.9t^2 + 200 results in t = 6.389 seconds
+37170 y = 3 (x-2)^2 - 27
= 3 (x^2-4x + 4) - 27
= 3x^2 -12x + 12 - 27
= 3x^2 -12x - 15
= 3(x^2-4x-5)
y = 3 (x-5)(x+1)
