Answer:
The correct answer is $800.
Step-by-step explanation:
Let the length and width of the field be equal to l meters and b meters respectively and l > b.
Area of the field is given by l × b = 400 square meters.
The river is supposed to be along the longest side so that the price of fencing the other three sides is minimum. Thus the total perimeter of the fence is b+ b+ l = 2b+l.
Total cost for fencing the other sides of the field = $ 10 × (2b + l)
The wall is supposed to be perpendicular to the river and thus the length of the wall is b meters.
Total cost for the wall is $ 20 × b
Therefore, the total price for making the field is given by
C = 10 × (2b + l) + 20 × b
⇒ C = 40b + 10l
⇒ C = 
+ 10l
To minimize the cost we differentiate the cost with respect to l and equate it to zero.
= 0 = - 
+ 10
⇒ 
= 1600
⇒ l = 40 ; [ negative sign neglected as length cannot be negative ]
⇒ b = 10
The second order derivative of C is positive giving the minimum value of the cost.
Thus the minimum cost required to make the field is given by $800.
Answer:
23 is 31/100
Step-by-step explanation:
not sure about the rest sorry :(
Answer:
Option B. Cosec θ = –5/3
Option C. Cot θ = 4/3
Option D. Cos θ = –4/5
Step-by-step explanation:
From the question given above, the following data were obtained:
Tan θ = 3/4
θ is in 3rd quadrant
Recall
Tan θ = Opposite / Adjacent
Tan θ = 3/4 = Opposite / Adjacent
Thus,
Opposite = 3
Adjacent = 4
Next, we shall determine the Hypothenus. This can be obtained as follow:
Opposite = 3
Adjacent = 4
Hypothenus =?
Hypo² = Opp² + Adj²
Hypo² = 3² + 4²
Hypo² = 9 + 16
Hypo² = 25
Take the square root of both side
Hypo = √25
Hypothenus = 5
Recall:
In the 3rd quadant, only Tan is positive.
Therefore,
Hypothenus = –5
Finally, we shall determine Sine θ, Cos θ, Cot θ and Cosec θ to determine which option is correct. This can be obtained as follow:
Opposite = 3
Adjacent = 4
Hypothenus = –5
Sine θ = Opposite / Hypothenus
Sine θ = 3/–5
Sine θ = –3/5
Cos θ = Adjacent / Hypothenus
Cos θ = 4/–5
Cos θ = –4/5
Cot θ = 1/ Tan θ
Tan θ = 3/4
Cot θ = 1 ÷ 3/4
Invert
Cot θ = 1 × 4/3
Cot θ = 4/3
Cosec θ = 1/ Sine θ
Sine θ = –3/5
Cosec θ = 1 ÷ –3/5
Invert
Cosec θ = 1 × –5/3
Cosec θ = –5/3
SUMMARY
Sine θ = –3/5
Cos θ = –4/5
Tan θ = 3/4
Cot θ = 4/3
Cosec θ = –5/3
Therefore, option B, C and D gives the correct answer to the question.
Answer:
8 bags
Step-by-step explanation:
You divided them by 20 which gives you 4. So you take the 3 and multiply by 4 which is 12 bags. And then you do the same for your bags which makes you do 2 times 4 which gives you 8. You take 20 - 12 and that leaves you with 8.
