If it's not what You are looking for type in the equation solver your own equation and let us solve it.
D( r )
r = 0
r = 0
r = 0
r in (-oo:0) U (0:+oo)
3/6 = 5/r // - 5/r
3/6-(5/r) = 0
3/6-5*r^-1 = 0
-5*r^-1 = -1/2 // : -5
r^-1 = 1/10
-1 < 0
1/(r^1) = 1/10 // * r^1
1 = 1/10*r^1 // : 1/10
10 = r^1
r = 10
r = 10
| -7+29h=-3 | | y=Ix^2-6x+5I | | x+(x+44)+60=180 | | B^2-18b+n=0 | | 1-2(x+4)=x+9-3x | | 2(2-x)-6(3x-10)=-5x-36 | | 120+3y=-5 | | 3/4n=13/4-18 | | 4x+3y=-11X-27-5y | | 12+6(z-2)=-3z+7 | | 4(7+7n)=224 | | -7r+2(r+1)=7-4r | | 1/3=r/18 | | (b+3)(5b-1)=0 | | 3/4n=-1.75-18 | | B/9=10/3 | | x-4/-24=-26 | | Y+8=2(y+1) | | H/10=15 | | -21c+20=-7 | | 18*4-5n=-36 | | 7a^2=-70 | | Y=-3x-1.5 | | 3(10x-1)= | | .15x+102=x | | ln(x)=4.158 | | z-24/14=-7 | | 8(1+6p)-4=196 | | z=ln(5+2i) | | 2x-5=-2x-2+4x | | -76+8x=3x+39 | | 30=b+12 |