Tolong bantu no 3 dan 4

bnintegral tertentu

3a

₀ᵇ ∫(4x-5) dx = - 3
[2x² - 5x ]ᵇ₀ = -3
2 b² - 5b = -3
2b² - 5b +3 = 0
(2b  - 3)(b - 1)= 0
b = -3/2    atau b  = 1
b > 0 ---> b = 1

3b)

₁²∫ p x² - 4x + 5 dx = 20
p(1/3 x³) - 2x² + 5x ]²₁ = 20
1/3 p(8-1) - 2(4-1) + 5(2-1) = 20
7/3 p - 6 + 5 = 20
7/3 p = 21
p = 21 (3/7) = 9


4.
f '(x) = 4 - 6x
f(3) =  -12

f(x)= ∫ f '(x) dx =  ∫ (4 - 6x) dx
f(x)= 4x - 3x² + c
f(3)= -12 --> 4(3) - 3(3)² + c = - 12
12 - 27 + c = -12
- 15 + c = -12
c = 3

a) f(x) = 4x - 3x² + 3  atau
f(x)= - 3x² + 4x + 3

b) ₁²∫ -3x² + 4x + 3 dx =

[x³ + 2x² + 3x]²₁ =  (8-1) + 2(4-1)+ 3(2-1) = 7+ 6 + 3= 16