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D( v )
v = 0
v = 0
v = 0
v in (-oo:0) U (0:+oo)
3-((4/5)*v)+10 = -(1/v-2) // + 1/v-2
1/v-((4/5)*v)-2+3+10 = 0
(-4/5)*v+1/v-2+3+10 = 0
1*v^-1-4/5*v^1+11*v^0 = 0
(11*v^1-4/5*v^2+1*v^0)/(v^1) = 0 // * v^2
v^1*(11*v^1-4/5*v^2+1*v^0) = 0
v^1
(-4/5)*v^2+11*v+1 = 0
(-4/5)*v^2+11*v+1 = 0
DELTA = 11^2-(1*4*(-4/5))
DELTA = 621/5
DELTA > 0
v = ((621/5)^(1/2)-11)/(2*(-4/5)) or v = (-(621/5)^(1/2)-11)/(2*(-4/5))
v = -5/8*((621/5)^(1/2)-11) or v = 5/8*((621/5)^(1/2)+11)
v in { -5/8*((621/5)^(1/2)-11), 5/8*((621/5)^(1/2)+11)}
v in { -5/8*((621/5)^(1/2)-11), 5/8*((621/5)^(1/2)+11) }
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