If it's not what You are looking for type in the equation solver your own equation and let us solve it.
D( t )
t = 0
t = 0
t = 0
t in (-oo:0) U (0:+oo)
6/t = 2/7 // - 2/7
6/t-(2/7) = 0
6/t-2/7 = 0
6*t^-1 = 2/7 // : 6
t^-1 = 1/21
-1 < 0
1/(t^1) = 1/21 // * t^1
1 = 1/21*t^1 // : 1/21
21 = t^1
t = 21
t = 21
| =-3x^2+9x+7 | | -3y=-2x-9 | | 17+3(a-2)-11-=-7(a+2)+14 | | (2c+3)(c+6)= | | 2ln(x+3)=4 | | (7t-2)-(-3+1)=-3(1+3t) | | X+21=4x+4 | | (7d-7)+2= | | 4+5x=-3 | | 7a-(1a-8)=1a+3 | | 120=8x+80 | | -3(4x-2)-6=-3(7x+1)-5 | | -25+m=-3(1+7n) | | -2x+4=5x+53 | | -3(2s-1)-3=-3(6s+6)-3 | | 42xy+56x-6y-8=0 | | 9n+-3=7(n+3)+2n | | f(x)=-11.246 | | 6y+4=25 | | X^2=48/16 | | -6v=-7 | | x+2x+3x+4x=132 | | Fg-9h=10jsolv | | Fg-9h=10jsolve | | c(2c+3)+6(2c+3)= | | -3(4s-2)-6=-3(7s+1)-5 | | 7(7x/1) | | f(x)=-27.083x-16.819 | | -2+3x+7-7x=-29 | | 12+x+4x-4+3x+3=180 | | 4n-9n-n= | | 6x-4=26-4x |