If it's not what You are looking for type in the equation solver your own equation and let us solve it.
D( x )
2*x^2+12 = 0
2*x^2+12 = 0
2*x^2+12 = 0
2*x^2 = -12 // : 2
x^2 = -6
x in (-oo:+oo)
(6*x^2+36)/(2*x^2+12) = 0
6*x^2 = -36 // : 6
x^2 = -6
x belongs to the empty set
| 6=v+5 | | 5=4x+31/3 | | 5=8+w | | 2=-3+w | | 3/8z-2/3z | | U-9=-2 | | 9x-3=3x-3 | | 6w+18-9w=-12 | | 2/3k+14k=22 | | 1/4y-5/12y | | 10.4+v/8=-2.4 | | t/6.87=-0.2 | | 115-5x=40x+20 | | x/4.4=15.6 | | k-2=-10 | | -6x=x+31 | | 87andh=14 | | a=3+25-7b | | -5/3=-3/5y-5/2 | | -2+n/2 | | x^2(x-1)=2+3x | | 7.1+y/5=-5.4 | | X(x-5)=3 | | (8+x)/4=-2 | | (-4/3)+(7/9w)=(-4/5) | | 5/6x+8=68 | | -p^3+4p^2+p-4= | | -p^3+4p^2*p-4= | | x-3/5=7/10 | | c^2-12c=-36 | | 4t-(1-t)=2(3t-4)-t | | 4p^2+p-4-p^3= |