Answer:
<u>(2) x </u>
<u> 4</u>
Step-by-step explanation:
Given the sqrt(x), x
zero
So, given sqrt(x -4), x -4
0
Now solve for x
x - 4
0
x
4
Answer:
The rate of decrease is: 
Step-by-step explanation:
Given

---- We used minus because the rate is decreasing
Required
Rate of decrease when: 
The volume of the cube is:

Differentiate

Make dV the subject

Divide both sides by dt

Given that:
and 



<em>Hence, the rate of decrease is: 43.2mm^3/min</em>
Answer: B
Step-by-step explanation:
Answer:
The car must drive at 108 km/h to cover the same journey.
Step-by-step explanation:
Given that:
Time taken by bus journey = 45 minutes = 
Speed of bus = 60 km/h
Distance of the journey = Speed * Time
Distance of the journey = 60 * 0.75 = 45 km
The car needs to cover 45 km in 25 minutes.
25 minutes = 
Distance = Speed * Time
45 = 
Speed = 
Speed = 108 km/h
Hence,
The car must drive at 108 km/h to cover the same journey.