Flights of leaping animals typically have parabolic paths. The figure illustrates a frog jump superimposed on a coordinate plane. The length of the leap is 9 feet, and the maximum height off the ground is 3 feet. find the equation of the parabola with zeroes at (0,0) and (9,0), and with a vertex of (4.5, 3).

Question

dumbcow · Answer

y = ax(x-9)
use vertex to solve for a
3 = a(4.5)(4.5-9)
3 = a(4.5)(-4.5)
3=20.25a
a = .148

--> y = .148x(x-9) = .148x^2 -1.33x

dumbcow · Answer

sorry i missed a neg sign, a should be negative

anonymous · Answer

Thank you so much! I had to fix it a tad bit. The equation is -.148x^2+1.33. But seriously, without this I'd be completely lost!

anonymous · Answer

Oh, just one more thing. How did you get the 1.33?

dumbcow · Answer

By distributing.... 9*.148=1.33

anonymous · Answer

oh I see it now. Sorry, and thanks again!