1-3/t-28/t^2=0

Solution for 1-3/t-28/t^2=0 equation:

D( t )

t^2 = 0

t = 0

t^2 = 0

t^2 = 0

1*t^2 = 0 // : 1

t^2 = 0

t = 0

t = 0

t = 0

t in (-oo:0) U (0:+oo)

1-(3/t)-(28/(t^2)) = 0

1-3*t^-1-28*t^-2 = 0

t_1 = t^-1

1-28*t_1^2-3*t_1^1 = 0

1-28*t_1^2-3*t_1 = 0

DELTA = (-3)^2-(-28*1*4)

DELTA = 121

DELTA > 0

t_1 = (121^(1/2)+3)/(-28*2) or t_1 = (3-121^(1/2))/(-28*2)

t_1 = -1/4 or t_1 = 1/7

t_1 = -1/4

t^-1+1/4 = 0

1*t^-1 = -1/4 // : 1

t^-1 = -1/4

-1 < 0

1/(t^1) = -1/4 // * t^1

1 = -1/4*t^1 // : -1/4

-4 = t^1

t = -4

t_1 = 1/7

t^-1-1/7 = 0

1*t^-1 = 1/7 // : 1

t^-1 = 1/7

-1 < 0

1/(t^1) = 1/7 // * t^1

1 = 1/7*t^1 // : 1/7

7 = t^1

t = 7

t in { -4, 7 }