Answer:
The correct option is;
21 ft
Step-by-step explanation:
The equation of the parabolic arc is as follows;
y = a(x - h)² + k
Where the height is 25 ft and the span is 40 ft, the coordinates of the vertex (h, k) is then (20, 25)
We therefore have;
y = a(x - 20)² + 25
Whereby the parabola starts from the origin (0, 0), we have;
0 = a(0 - 20)² + 25
0 = 20²a + 25 → 0 = 400·a + 25
∴a = -25/400 = -1/16
The equation of the parabola is therefore;
To find the height 8 ft from the center, where the center is at x = 20 we have 8 ft from center = x = 20 - 8 = 12 or x = 20 + 8 = 28
Therefore, plugging the value of x = 12 or 28 in the equation for the parabola gives;
.
Answer:
x = √K - 2xh - h²/a
Step-by-step explanation:
a(x+h)²=k
a * x² + 2xh + h² = k
a * x² = K - 2xh - h²
x² = K - 2xh - h²/a
x = √K - 2xh - h²/a
Answer:
y=1/3x-3 2/3 (y equals one third times x minus three and two thirds)
Explanation:
Slope = rise (Δy) over run (Δx). Looking at the two points, (-1, -4) is furthest to the left. The x value increases by 3, and the y value increases by 1. That means slope = 1/3. Now, plug it into the slope equation y=mx+b, m being slope. We get y=1/3x+b. To find b (the y-intercept), plug in one of the points into the equation. So -4=1/3·(-1) +b. 1/3 times -1 is -1/3. Now we have -4=-1/3+b. -4-1/3= -11/3 (or negative 3 and 2/3). That means the y intercept is -3 2/3. Now we get the equation. y=1/3x-3 2/3
