S(t) =2t^4+3t^2-t+квадратный кореньt^3 v, a?
v(t)=S`(t)=(2t^4+3t^2–t+sqrt(t^3))`=8t^3+6t-1+(3/2)sqrt(t) a(t)=v`(t)=(8t^3+6t-1+(3/2)sqrt(t))`=24t^2+6+(3/2)*(1/2)*(1/sqrt(t))=24t^2+6+(3/4)*(1/sqrt(t))