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 = 0
x = 0
x = 0
x in (-oo:0) U (0:+oo)
3*4-12*x-x-3 = 1/x // - 1/x
3*4-12*x-x-(1/x)-3 = 0
3*4-12*x-x-x^-1-3 = 0
9*x^0-13*x^1-1*x^-1 = 0
(9*x^1-13*x^2-1*x^0)/(x^1) = 0 // * x^2
x^1*(9*x^1-13*x^2-1*x^0) = 0
x^1
9*x-13*x^2-1 = 0
9*x-13*x^2-1 = 0
DELTA = 9^2-(-13*(-1)*4)
DELTA = 29
DELTA > 0
x = (29^(1/2)-9)/(-13*2) or x = (-29^(1/2)-9)/(-13*2)
x = (29^(1/2)-9)/(-26) or x = (29^(1/2)+9)/26
x in { (29^(1/2)-9)/(-26), (29^(1/2)+9)/26}
x in { (29^(1/2)-9)/(-26), (29^(1/2)+9)/26 }
| 5+8+x=23 | | 15x+.8+6x-8=180 | | 8s+9=7s-6 | | -x^2+6+2x^2+3x-5= | | 4+x(2)=10 | | 6x^3+2x^2-8=0 | | 12x^3=0 | | 5x-8=11-19x | | 0.2d=3d+2.1 | | 12n+1.5a=3a | | 2x^2+5+12=0 | | 3x+4y=7x-9 | | w/8=12.8 | | 8+7x+3x=-62 | | 18y^2-32=0 | | (38X)+(17x(2X))=1520 | | 3-x(4)=5 | | 3z-4z+8z= | | 3(-2x+1)=-(x+1) | | y/-3=11 | | 4s-5s=28 | | 2z-5z+6z= | | x-2/4=x+4/2 | | 36+5j=9j | | x+16=16+2x-3x | | 2x+4(x-1)-9x+7= | | 3x-5/4=-5/7 | | (x-2)(2x-7)= | | (6y+6)-(3+5y)=11 | | 3x(4)=5 | | 74-15x=149 | | 4(9c-1)-8=34c+4 |