ANSWER
EXPLANATION
We want to find the exact value of cos(150°).
150° makes an angle of 30° with the positive direction of the x-axis and it is also in the second quadrant.
The cosine ratio is negative in the second quadrant.
Using the unit circle,
Answer:
81 cubic ft. is the answer.
3 weeks
Step-by-step explanation:
To find the number of weeks, we have to equate the amount already saved and planned to save by both each week.
So we can write the expression as,
Let w be the number of weeks.
25 + 5w =16 + 8w
Grouping the terms as,
25 - 16 = 8w - 5w
9 = 3w
Dividing both sides by 3, we will get,
3w/3 = 9/3
w = 3
So number of weeks = 3
Answer:
correct
Step-by-step explanation:
x means up and down and it is at -3
y means side to side and it is at -7
If y = cos(kt), then its first two derivatives are
y' = -k sin(kt)
y'' = -k² cos(kt)
Substituting y and y'' into 49y'' = -16y gives
-49k² cos(kt) = -15 cos(kt)
⇒ 49k² = 15
⇒ k² = 15/49
⇒ k = ±√15/7
Note that both values of k give the same solution y = cos(√15/7 t) since cosine is even.
