You are building an arc entrance over a roadway. The road under
the arc is 20 feet wide with a 6-foot sidewalk on both sides of
the road. Write an equation to accomplish this task.

Respuesta :

The equation of the parabolic arc that accomplishes this task is:

y = (-k/256)(x - 16)² + k.

In which k is the maximum height of the arc.

What is the equation of a parabola given it’s vertex?

The equation of a quadratic function, of vertex (h,k), is given by:

y = a(x - h)² + k

In which a is the leading coefficient.

For this problem, the arc has these following characteristics:

  • Parabolic.
  • Concave down.
  • The peak is at half the road.

The road under the arc is 20 feet wide with a 6-foot sidewalk on both sides of the road, hence it's total length is of 20 + 2 x 6 = 32 feet, and the peak of the arc will be at h = 16.

Hence:

y = a(x - 16)² + k.

The height is of 0 at x = 0 and x = 32, hence:

0 = 256a + k.

a = -k/256

y = (-k/256)(x - 16)² + k.

In which k is the maximum height of the arc.

More can be learned about the equation of a parabola at https://brainly.com/question/24737967

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