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.
In order to add these fractions we have to make a common denominator.
1/5 can turn into 2/10 Its the same thing. And its easier to solve with.
now lets multiply.
× 
Now we add across
2 + 1 = 3
------------
10 + 10 = 10 ( When adding fractions like these the denominator stays the same)
So your answer is...
Good Luck! :)
Answer:
34 km/h
Step-by-step explanation:
speed = distance/time
Distance = 17km
Time = 0.5 or 1/2 hours because it's 30 minutes between 17:15 to 17:45, and 30 minutes is a half of an hour and you want km over hours
So
speed = 17/0.5
speed = 34 km/h
Answer:
i think it is c because its a complete question and sentence if im wrong tell me ( ;
brainlyest would be nice btw ( ;
Step-by-step explanation:
