please tolong bantu di jawab.

Integral Tertentu
1.

⁴₁∫ (√x  - 2)(2√x +1) dx =
= ₁⁴∫ (2x  + √ x - 4√x - 2) dx
= ₁⁴∫ (2x - 3√x -2) dx
= ₁⁴∫ 2x - 3x¹/²  - 2 dx
= [ x² - 2x³/² - 2x]⁴₁
= (4² -1²) - 2(4³/² - 1³/²) - 2(4 -1)
= (16-1) - 2(8-1) - 2(3)
= 15 - 14 - 6
= - 5

2)
ᵇ₁∫(3x² + 6x + 1) dx = 52

= [ x³ + 3x² + x]ᵇ₁ = 52
= (b³ + 3b² +b) - (1 +3 + 1) = 52
b³+ 3b² + b - 57 = 0
(b-3)(b²+6b +19) = 0
b - 3 = 0 atau b² + 6b + 19 = 0 ( D < 0)
b = 3