A building has an entry the shape of a parabolic arch 84 ft high and 42 ft wide at the base as shown below.
http://prntscr.com/6sm50g
Find an equation for the parabola if the vertex is put at the origin of the coordinate system.

Question

A building has an entry the shape of a parabolic arch 84 ft high and 42 ft wide at the base as shown below. 
http://prntscr.com/6sm50g
Find an equation for the parabola if the vertex is put at the origin of the coordinate system.

sleepyjess · Answer

I believe it is $x^2 = -5.3y$, but I'm having second thoughts that it is $y^2 = -5.3x$

jdoe0001 · Answer

hmm

jim_thompson5910 · Answer

hint: the point (21, -84) lies on this parabola

you take the 42 ft and cut it in half because the line of symmetry means one side is mirrored to the other

jdoe0001 · Answer

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