Mon premier delta était faux. 
Encore un + qui est devenu -.
Deltax = 4m²+2m+1/4
Deltam = 2²-4*1/4*4 = 4-4 = 0
m0 = -b/2a = -2/2*4 = -2/8 = -1/4
=> Deltax = 4(m+1/4)² = 2²*(m+1/4)²
mx²+x(1-4m)/2-1 = 0
m = 1/4 => deltax = 0
x0 = -b/2a = -(1-4m)/2*1/2m = -(1-4m)/4m = -(1+1)/(-1) = -2/(-1) = 2
m quelconque => delta x positif
x1 = (-b-Vdeltax)/2a = 1/2m*(-(1-4m)/2-2(m+1/4)) = 1/2m*((-2+8m-8m-2)/4) = 1/2m*(-4/4) = -1/2m
x2 = (-b+Vdeltax)/2a = 1/2m*(-(1-4m)/2+2(m+1/4)) = 1/2m*((-2+8m+8m+2)/4) = 1/2m*16m/4 = 1/2m*4m = 2
Il n'y a que 2 solutions apparemment, x1 = -1/2m et x2 = 2. 