Please help!
The suspension cables between the two towers of the Mackinac Bridge in Michigan form a parabola that can be modeled by the graph of y = 0.000097x2 − 0.37x + 540 where x and y are measured in feet.

What is the height of the cable above the water at its lowest point?

Question

Please help!
The suspension cables between the two towers of the Mackinac Bridge in Michigan form a parabola that can be modeled by the graph of y = 0.000097x2 − 0.37x + 540 where x and y are measured in feet.

What is the height of the cable above the water at its lowest point?

anonymous · Answer

@whpalmer4 can you please help me

whpalmer4 · Answer

Here's the formula for finding the vertex of a parabola in the form $$y = ax^2+bx+c$$

$$x = -\frac{b}{2a}$$$$y = a(\frac{b^2}{4a^2}) + b(\frac{-b}{2a}) + c = \frac{b^2}{4a}-\frac{b^2}{2a}+c = -\frac{b^2}{4a}+c$$or just plug $x$ into the original formula

anonymous · Answer

@whpalmer4 thank you!