Answer:
y ≈ 16.33
Step-by-step explanation:
∆SPQ is a 30-60-90 right triangle
PS:QS:PQ = 1:2:√3
QS/PQ = 2/√3
QS/PQ = QS/10
QS/10 = 2/√3 Multiply each side by 10
QS = 20/√3
∆RSQ is a 45-45-90 right triangle.
∴ RS = QS = 20/√3
RS² + QS² = QR²
(20/√3)² + (20/√3)² = y²
400/3 + 400/3 = y²
800/3 = y² Take the square root of each side
y = √(800/3)
= 20√(2/3)
= (20√6)/3
≈ 16.33
Answer:
The number of feet of fencing that he needs will be equal to the perimeter of the circular patio.
We know that the perimeter of a circle of radius R is equal to:
P = 2*pi*R
where pi = 3.14
Then if the radius of the patio is 70ft, the perimeter of the patio will be:
P = 2*3.14*70ft = 439.6 ft
Then he needs 439.6 ft of fencing to enclose the patio.
You set up was almost accurate. Remember the arc length formula:
If f'(y) is continuous on the interval [a,b], then the length of the curve x = f(y), a ≤ y ≤ b should be;
L = ∫ᵇ ₐ √1 + [f'(y)]^2 * dy
We have to find the length of the curve given x = √y - 2y, and 1 ≤ y ≤ 4. You can tell your limits would be 1 to 4, and you are right on that part. But f'(y) would be rather...
f'(y) = 1/(2√y) - 2
So the integral would be:
∫⁴₁ √1 + (1/(2√y) - 2)² dy
Using a calculator we would receive the solution 5.832. Their is a definite curve, as represented below;
Answer:
The full answer in the media.Good luck!