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D( x )
(-2*x^3)^-3 = 0
-2*x^3 = 0
(-2*x^3)^-3 = 0
(-2*x^3)^-3 = 0
-1/8*x^-9 = 0 // : -1/8
x^-9 = 0
x należy do O
-2*x^3 = 0
-2*x^3 = 0
-2*x^3 = 0 // : -2
x^3 = 0
x = 0
x in (-oo:0) U (0:+oo)
((-3*x^5)^2)/((-2*x^3)^-3) = 0
-72*x^19 = 0 // : -72
x^19 = 0
x = 0
x in { 0}
x belongs to the empty set