Answer:
Step-by-step explanation:
put x=r cos θ
y=r sin θ
r²cos²θ-r²sin²θ=3rsin θ
r²(cos²θ -sin²θ)=3r sin θ
r²cos 2θ=3rsinθ
r cos 2θ=3 sin θ
r=3sec 2θ sin θ
9) 83 (9
-81
___
2
Mixed fraction formula: Quotient Reminder/Dividend
Q = 9 R=2 D=9
So, 83/9 in mixed fraction is 9 2/9
HOPE THIS HELPS!!!!
A) Diagram
Below is a sketch of the recctangular lawn (the inside rectangle) and the gravel border.
6 ft + 150 yards + 6 ft
-------------------------------
| |
| --------------------- |
| | | |
| | | | 6 ft + 80 yard + 6 ft
| | | |
| --------------------- |
| |
|------------------------------|
B) How many square feet of the gravel will surround the lawn?
Conversion: 1 yard = 3 feet
=> 80 yard = 80*3 feet = 240 feet
=> 150 yard = 150 * 3 feet = 450 feet
Area of the external rectangle = (6 ft + 240 ft + 6 ft) (6 ft + 450 ft + 6 ft) = 252 ft * 462 ft = 116,424 ft^2
Area of the internal rectangle = 240 ft * 450 ft = 108,000 ft^2
Area of the gravel border = 116,424 ft^2 - 108,000 ft^2 = 8424 ft^2
answer: 8424 ft^2
C) volume
volume = area of the base * depth
2 inches = 2/12 ft = 1/6 ft
=> volume = 8424 ft^2 * 1/6 ft = 1404 ft^3
answer: 1404 ft^3
C) cost
1 yard^3 = $ 30
1yard ^3 = (3 feet)^3 = 27 ft^3
=> cost = $ 30 / 27 ft^3
=> 1404 ft^3 * $30 / 27 ft^3 = $ 1560
answer: $ 1560
C should be the correct answer
