' - - Rotate Parabola to an angle that places its minimum on the rotated axes.
pi = 3.14159

b = -1                            ' Trial size.
F{x} =  x^2 + b * x         ' 2nd degree with coefficient "b" to be adjusted.
A<x> = <x, F, 0 >

th = ATan[-b] 

B<x> = vRotz[A, th]

Plot[A, B,  {x, -1.5, 2, 100}]
<x = 1>

' Place a minus in front of the x^2 term and repeat the analysis. 


