tolong bantu ya, pake rumus. no 30dan31

30) h(t) = 8 + 10t - 5/2 t^2
h'(t) = 10 - 5t = 0 => -5t = -10 => t = 2
h(2) = 8 + 10(2) - 5/2 (2)^2 = 8 + 20 - 10 = 18 m

31) int 3x^2 (2x + 1)^2 dx
Dengan menggunakan cara tabel
Turunan ... Integral
(+) 3x^2 .......... (2x + 1)^2
( - ) 6x ............. 1/2 . 1/3 (2x + 1)^3 = 1/6 (2x + 1)^3
(+) 6 ................ 1/6 . 1/2 . 1/4 (2x + 1)^4 = 1/48 (2x + 1)^4
( - ) 0 ............. 1/48 . 1/2 . 1/5 (2x + 1)^5 = 1/480 (2x + 1)^5
Kali silang
= 3x^2 . 1/6 (2x + 1)^2 - 6x . 1/48 (2x + 1)^4 + 6 . 1/480 (2x + 1)^5 + C
= 1/2 x^2 (2x + 1)^2 - 1/8 x (2x + 1)^4 + 1/80 (2x + 1)^5 + C