If it's not what You are looking for type in the equation solver your own equation and let us solve it.
D( a )
a = 0
a = 0
a = 0
a in (-oo:0) U (0:+oo)
2*(a-2) = -(a-(1/a)-4) // + a-(1/a)-4
2*(a-2)+a-(1/a)-4 = 0
2*(a-2)+a-a^-1-4 = 0
2*(a-2)+a-1/a-4 = 0
(2*a*(a-2))/a+(a^2)/a-1/a+(-4*a)/a = 0
2*a*(a-2)+a^2-4*a-1 = 0
3*a^2-4*a-4*a-1 = 0
3*a^2-8*a-1 = 0
3*a^2-8*a-1 = 0
3*a^2-8*a-1 = 0
DELTA = (-8)^2-(-1*3*4)
DELTA = 76
DELTA > 0
a = (76^(1/2)+8)/(2*3) or a = (8-76^(1/2))/(2*3)
a = (2*19^(1/2)+8)/6 or a = (8-2*19^(1/2))/6
(a-((8-2*19^(1/2))/6))*(a-((2*19^(1/2)+8)/6)) = 0
((a-((8-2*19^(1/2))/6))*(a-((2*19^(1/2)+8)/6)))/a = 0
((a-((8-2*19^(1/2))/6))*(a-((2*19^(1/2)+8)/6)))/a = 0 // * a
(a-((8-2*19^(1/2))/6))*(a-((2*19^(1/2)+8)/6)) = 0
( a-((2*19^(1/2)+8)/6) )
a-((2*19^(1/2)+8)/6) = 0 // + (2*19^(1/2)+8)/6
a = (2*19^(1/2)+8)/6
( a-((8-2*19^(1/2))/6) )
a-((8-2*19^(1/2))/6) = 0 // + (8-2*19^(1/2))/6
a = (8-2*19^(1/2))/6
a in { (2*19^(1/2)+8)/6, (8-2*19^(1/2))/6 }
| 102=u-66 | | (-2+6i)(3-4i)=0 | | 10+3[9-4(5-2)]= | | .33333+7=13 | | 4.5y+3(2y)=252 | | 4j-3j+3=-32 | | 6/(7+3i)=0 | | .33+7=13 | | .55/100= | | (6)/(7+3i) | | 3(86)+y=34 | | 3x/4+7=10 | | 7(2+2x)=45 | | 6(2x-3)= | | 0=x^2+24x-180 | | -2+y=-3x | | 5x^2+30=90 | | (6-7i)(6-7i)=0 | | (6-7i)= | | 3(-9)+y=34 | | 2x+4=(54-38).2 | | 2/3x+2-6x=-154/3 | | -12-6x=14-7x | | 5x+4=(54-38).2 | | (4x-5)(1+x)=0 | | 3m^4/6m^2 | | 7(2ab-1a)=2(2a-1ab) | | 3c+17c=5 | | y^4-3y^3+3y^2-1=0 | | 3(2x-3)+2x-2=-91 | | 9s+22-w= | | 3(-4x-5)-x+4=-50 |