The surface of a road curves like a parabola to allow water to drain off of it. The given equation shows the surface height, y, in feet above the base at a point x feet from the left edge of the road.y=−0.0015x(x−40)The base has the same width as the road. What is the width of the road in feet?
Q. The surface of a road curves like a parabola to allow water to drain off of it. The given equation shows the surface height, y, in feet above the base at a point x feet from the left edge of the road.y=−0.0015x(x−40)The base has the same width as the road. What is the width of the road in feet?
Identify x-intercepts: Identify the x-intercepts of the parabola to determine the width of the road.The equation of the parabola is given by y=−0.0015x(x−40). The x-intercepts occur when y=0.0=−0.0015x(x−40)
Solve equation for x: Solve the equation for x to find the x-intercepts.We can factor out x from the equation:0=x(−0.0015x+0.0015×40)0=x(−0.0015x+0.06)The x-intercepts are x=0 and x=40.
Determine road width: Determine the width of the road using the x-intercepts.The width of the road is the distance between the two x-intercepts. Since the x-intercepts are 0 and 40, the width of the road is 40 feet.