Using the formula that Melody posted.... I get Karlee has ( r = .006666667 I think this is where our answers differ) 894,064.89
and Chase has 702 856.24
Start with vertex form of a parabola
y = a (x+2)^2 -1 sub in point 0,6 to find a = 7/4
y = 7/4 (x+2)^2 -1
I do not know the units but ( 9.4 x 108 ) / ( 8.760 x 103) = .................... units/hr
Just put '1' in for 'x' and calculate 'b'
3 (14) - 7 (13) - 2(12) - b (1) + 1 = 1 solve for 'b'
ax^2 + 20x + 7 = 14x + 9 re-arrange
ax^2 + 6x -2 = 0 for only one solution ( one double root) the discriminant of the Quadratic Formula must = 0
\(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\)
b^2 - 4ac = 0
(6)^2 - 4 (a)(-2) = 0
8a = -36
a = -4.5
Probably easiest to use Quadratic Formula
\(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\) a = -.015 b = 1.875 c = 1.59375
y = ( x - 125.844)(x + .844297)
Try (0,0)
x^2+y^2-6x+4y+4=0 put into standard circle equation form
x^2 - 6x + y^2 + 4 = - 4 now, complete the square for x and y
(x-3)^2 + ( y+2)^2 = - 4 + 9 + 4
(x-3)2 + ( y+2)2 = 9 center is thus seen as 3, -2 and radius = sqrt 9 = 3
(2x -1 )(x +3 ) = 0 shows x = 1/2 and -3
Seven