Answer:
8 seconds
Step-by-step explanation:
Given
h = - 5t² + 40t
When the object hits the ground then h = 0
Substitute h = 0 into the function and solve for t
- 5t² + 40t = 0 ← factor out - 5t from each term
- 5t(t - 8) = 0
Equate each factor to zero and solve for t
- 5t = 0 ⇒ t = 0
t - 8 = 0 ⇒ t = 8
t= 0 denotes the time of launch
t = 8 denotes the time it hits the ground
cos (2x) = cos x
2 cos^2 x -1 = cos x using the double angle formula
2 cos ^2 x -cos x -1 =0
factor
(2 cos x+1) ( cos x -1) = 0
using the zero product property
2 cos x+1 =0 cos x -1 =0
2 cos x = -1 cos x =1
cos x = -1/2 cos x=1
taking the arccos of each side
arccos cos x = arccos (-1/2) arccos cos x = arccos 1
x = 120 degrees x=-120 degrees x=0
remember you get 2 values ( 2nd and 3rd quadrant)
these are the principal values
now we need to add 360
x = 120+ 360n x=-120+ 360n x = 0 + 360n where n is an integer
The answer is 492.307
The number after the thousandths is 9 - greater than 5 - so we round 6 up to 7.
Answer:
The answer is -77
Step-by-step explanation:
Hope this helped! Have a great day!