
Actually Welcome to the Concept of the derivatives.
Hence, y = 3 sin(-4x), we use the chain rule here.
dy/dx =3 ( cos(-4x).-4)
====> dy/dx = -12 cos(-4x)
Your answer is 80 mins, or an hour and 20 mins. You simply turn that fraction to a decimal by diving 3 with 5. This should turn out to be 0.6. Then you multiply the 24 mins with the 2 miles and it turns out to be 48. After this, you divide 48 by 0.6 and you get 80.
Answer:
9.08 hours
Step-by-step explanation:
in order to fill 1 pool
fill rate by pipe = 1 pool / 15 hours = 1/15 pool per hour
fill rate by hose = 1 pool / 23 hours = 1/23 pool per hour
combined rate = fill rate by pipe + fill rate by pool
= 1/15 + 1/23 = 38/345 pool per hour
since:
38/345 pool -----------> will take 1 hour
1 pool --------------------> will take 1 hour x (345/38) = 9.08 hours