After a dreary day of rain, the sun peeks through the clouds and a rainbow forms. You notice the rainbow is the shape of a parabola.. . Create an equation. Use the graph below to create the equation of the rainbow parabola.
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Substitute third point (0, 36) into the above equation to solve for a.
y = a(x + 6)(x - 6)
36 = a(0+6)(0-6)
36 = a(-36)
a = -1
So the equation is
y = -(x + 6)(x - 6)