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)
8.87/r = 22.175 // - 22.175
8.87/r-22.175 = 0
8.87*r^-1 = 22.175 // : 8.87
r^-1 = 2.5
-1 < 0
1/(r^1) = 2.5 // * r^1
1 = 2.5*r^1 // : 2.5
0.4 = r^1
r = 0.4
r = 0.4
| 7x-5x+4=24 | | 7x-(2x+5)-3=3x+x+5+x+1 | | 50825/2675 | | 14X=2B | | -14-9x=8(10+x) | | 1/6a=18 | | 3b+10=110-b | | 1/2t=18 | | 7(u-6)-8=-4(-5u+9)-9u | | 2z+13=-5 | | 6r^2-5rs+s^2=0 | | 4(-2y+6)=-6(y-5) | | x^2=-16/17 | | s(t)=-16t^2+128t+224 | | 5+34=-2(1-7n) | | 3+6z=13+16z | | 7x-13=3(x-7) | | 5-6k+3k-9= | | 4sinx+4=2 | | 4(1+8x)=2(3-7x) | | 6x-6-10x= | | 80-3s=5s+8 | | 2.5x-1.5=3.5 | | -48+5x=43-2x | | -2(2t+4)=4t-8 | | 16(3x-12)=12(-16+4x) | | -2x-(-6x-8)+4=2x-(-2x-12) | | 7x^2+8x-15=49-40x | | X+.5y=200 | | 42=26m | | 29-15= | | k/16=15 |