Question

The path of the water in a pond fountain can be modeled by y=-0.1x^2+2.8x , where x and y are measured in feet. The x -axis represents the surface of the pond. Find the width of the path at the surface of the pond and the height of the path.

Width: ___ ft
Height: ___ ft

Answer 1

the width of the path at the surface of the pond is 14 feet, and the height of the path above the surface of the pond is 19.6 feet.

Explanation:

To find the width of the path at the surface of the pond, we need to find the x-coordinate of the vertex of the parabola y = -0.1x^2 + 2.8x. The x-coordinate of the vertex can be found using the formula:

x = -b/2a

where a = -0.1 and b = 2.8. Substituting these values, we get:

x = -2.8 / 2(-0.1) = 14

So the width of the path at the surface of the pond is 14 feet.

To find the height of the path, we need to find the y-coordinate of the vertex of the parabola y = -0.1x^2 + 2.8x. The y-coordinate of the vertex is given by:

y = f(x) = -0.1(x - h)^2 + k

where (h,k) is the vertex of the parabola. To find the vertex, we can use the formula:

h = -b/2a and k = f(h)

Substituting a = -0.1 and b = 2.8, we get:

h = -2.8 / 2(-0.1) = 14

k = f(14) = -0.1(14)^2 + 2.8(14) = 19.6

So the vertex of the parabola is (14, 19.6), which means the maximum height of the path above the surface of the pond is 19.6 feet.

Therefore, the width of the path at the surface of the pond is 14 feet, and the height of the path above the surface of the pond is 19.6 feet.