From simple queries to complex problems, IDNLearn.com provides reliable answers. Our platform offers reliable and comprehensive answers to help you make informed decisions quickly and easily.

Each of the "golden arches" at a McDonald's restaurant is in the shape of a parabola. Each arch is modeled by: h(x)= -x^2+6x, where h(x) is the height of the arch (in feet) at a distance x(in feet) from one side.
a. Find the equation of the axis of symmetry.
b. How high is the arch at the axis of symmetry?


Sagot :

a.
The equation of the axis of symmetry of a parabola [tex]y=ax^2+bx+c[/tex] is [tex]x=-\frac{b}{2a}[/tex].

[tex]h(x)=-x^2+6x \\ a=-1 \\ b=6 \\ \\ \hbox{the axis of symmetry:} \\ x=-\frac{6}{2 \times (-1)} \\ x=-\frac{6}{-2} \\ x=-(-3) \\ x=3[/tex]

The equation of the axis of symmetry is x=3.

b.
[tex]x=3 \\ \\ h(x)=-x^2+6x \\ h(3)=-3^2+6 \times 3 \\ h(3)=-9+18 \\ h(3)=9[/tex]

At the axis of symmetry the arch is 9 feet high.