Cos^4(x) =
(cos²x)² =
(1-sen²x)² =
1² - 2*1*sen²x + sen^4x =
1 - 2sen²x + sen^4x
1020 + 1020 = 2040
%60 of 1020 is:612
2040+612=2652
so third one is true
The domain is the limits of the function. Since time doesnt go negative, start with 0. At time 0, the height is
-16(0)^2 + 144 = 144ft
Then, solve for t to find the upper limit for t, which is when the height is zero (since you're dropping the object).
-16t^2 + 144 = 0
-16t^2 = -144
t^2 = 9
t = sqrt(9)
t = 3
The domain is 0 to 3 seconds.
The answer would be,
0, -4, -3.8, 3.3
