Задача 1:
y' =a·b·x^(b-1) - 2·(b-a)·x^(b-a-1) +4·1/3·x^(1/3-1) - 0 =
=ab·............................................+4/3·x^(-2/3)
y'' = ab·(b-1)·x^(b-2) - 2(b-a)·(b-a-1)·x^(b-a-2) + 4/3·(-2/3)·x^(-5/3)
y'' = 1·3·2·x - 2·2·1·x^0 - 8/9·x^(-5/3) = 6x -4 - 8/9·x^(-5/3)
задача 2:
1) ??? не видно к чему стремится x
2) x→1 lim (√(2x+7)]/[(x+3)·(x-1)
обозначим y= √(2x+7) ⇒ y→3 ; x = (y²-7)/2 ⇒
(x+3)·(x-1) = (y²-1)/2 ·(y²-9)/2 = [(y²-1)·(y+3)]/4 · (y-3) =A
≡ y→3 lim(y - 3)/A = lim 4/[(y²-1)·(y+3)] = 4/(8·6) = 1/12
3)