If it's not what You are looking for type in the equation solver your own equation and let us solve it.
D( x )
x^2 = 0
x^2 = 0
x^2 = 0
1*x^2 = 0 // : 1
x^2 = 0
x = 0
x in (-oo:0) U (0:+oo)
1-(4/(x^2)) = 0
1-4*x^-2 = 0
-4*x^-2 = -1 // : -4
x^-2 = 1/4
-2 < 0
1/(x^2) = 1/4 // * x^2
1 = 1/4*x^2 // : 1/4
4 = x^2
x^2 = 4 // ^ 1/2
abs(x) = 2
x = 2 or x = -2
x in { 2, -2 }
| 12z^2-8z-15=0 | | 2/3(9x-12)=28 | | (y^2+y-6)(y^2-6y+9)-2(y^2-9)=0 | | (y-9)-(Y+8)=6y | | 3x^2-130x-5600=0 | | x-0.4x=107820 | | x^2=-242 | | 7x-2y=32 | | x^4-4x^3+x^2+4x+1=0 | | 8t=51 | | x^2+0.2x-0.24=0 | | Y=x+6x+10 | | -6 x+ 4 y= 12 | | a+a+1+a+2+a+3=34 | | X^3+7x^2+10x-6=0 | | 3=2+2b | | 3x^2+22x-2600=0 | | Y=x^2-14x-59 | | 7+4x=3y | | 5g-6-4-5g= | | -16t^2+2304=0 | | -16t+2304=0 | | 3w/2w-6 | | 4(2x+5)=3(5x-6) | | 4x^2+13x=0 | | (2x+3)(x-1)+(3x-5)(2x+7)=0 | | 9x^2-2X=5 | | -5(5r+9)+5(r-6)= | | 12=3600/r | | 55-x=-12 | | x+5y+2x+2y+3=90 | | 3872=1/2m22 |