Answer: the rate at which the distance between the boats is increasing is 68 mph
Step-by-step explanation:
The direction of movement of both boats forms a right angle triangle. The distance travelled due south and due east by both boats represents the legs of the triangle. Their distance apart after t hours represents the hypotenuse of the right angle triangle.
Let x represent the length the shorter leg(south) of the right angle triangle.
Let y represent the length the longer leg(east) of the right angle triangle.
Let z represent the hypotenuse.
Applying Pythagoras theorem
Hypotenuse² = opposite side² + adjacent side²
Therefore
z² = x² + y²
To determine the rate at which the distances are changing, we would differentiate with respect to t. It becomes
2zdz/dt = 2xdx/dt + 2ydy/dt- - - -- - -1
One travels south at 32 mi/h and the other travels east at 60 mi/h. It means that
dx/dt = 32
dy/dt = 60
Distance = speed × time
Since t = 0.5 hour, then
x = 32 × 0.5 = 16 miles
y = 60 × 0.5 = 30 miles
z² = 16² + 30² = 256 + 900
z = √1156
z = 34 miles
Substituting these values into equation 1, it becomes
2 × 34 × dz/dt = (2 × 16 × 32) + 2 × 30 × 60
68dz/dt = 1024 + 3600
68dz/dt = 4624
dz/dt = 4624/68
dz/dt = 68 mph
Answer:

Step-by-step explanation:
Complete question is given below
Add:-
ab-bc+ac,bc-ca+ab,ca-ab-2bc
We have to find the result after addition
Now, adding all expression
We get

Combine like terms then, we get


Hence,
Divide 22.2 by 4 since the perimeter is the outside and there are 4 edges
Answer:
The number of elephant ears that must be sold to maximize profit is 400.
Step-by-step explanation:
Given that,
The profit that a vendor makes per day is given by
P(x)= - 0.004x² +3.2 x -200
where x is number of elephant ears.
P(x)= - 0.004x² +3.2 x -200
Differentiating with respect to x
P'(x)= - 0.008x+3.2
Again differentiating with respect to x
P''(x) = -0.008
For maximum or minimum P'(x)=0
- 0.008x+3.2=0
⇒0.008x=3.2

⇒ x = 400

Since at x=400, P''(x)<0, the profit is maximize.
P(400) = -0.004×400²+3.2×400-200
=440
The number of elephant ears that must be sold to maximize profit is 400.
Answer:
that answers wrong
Step-by-step explanation: