Just saying you have a 25% chance of getting it right if you guess
Answer:
-7/25.
Step-by-step explanation:
From the given point P we see that the hypotenuse = √(3*2 + 4^2) = 5.
So cos θ = 3/5
cos 2 θ = 2 cos^2 θ - 1
= 2 * (3/5)^2 -1
= -7/25.
The toy rocket hits the ground when h(t) = 0.
So, h(t) = 0 = -9t^2 + 81.
Solving the equation,
-9t^2 = -81
Dividing by -9
t^2 = 9
Taking the square root.
t = 3
The answer is 3 seconds.
