S'(t) =t³ +2t² ; t₁=3c.
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a(t₁) =a(3) -->?
скорость: V(t) = S'(t) =(t³ +2t²) ' =(t³) ' +(2t²) ' =3t² +2(t²) ' = 3t² +4t.
ускорение: a(t) =V'(t) =S ''(t) ;
a(t) =(3t² +4t)' = (3t²)' +(4t)'=3(t²)' +4*(t)' =3*2t +4*1 =6t+4 ;
a(3) =6*3+4 =22.