3 / 4 2\ \-2*a *b /
((-2*a^4)*b^2)^3 при a = -1
((-2*a^4)*b^2)^3
((-2*(-1)^4)*b^2)^3
((-2)*b^2)^3
-8*b^6
12 6 -8*a *b
-8.0*a^12*b^6
6 12 b *-8*a