Someone pleaseeee help I dont get how this question would involve integration

4/3 units²

Step-by-step explanation:

First find the x-coordinates of B

x² - 4x + 3 = 0

x² - 3x - x + 3 = 0

(x - 3)(x - 1) = 0

x = 3 for B (x = 1 is for the first x-intercepts)

Now integrate the curve with limits 3 to 4

Integration:

(x³/3) - 4(x²/2) + 3x

x³/3 - 2x² + 3x

Upper limit - Lower limit

[4³/3 - 2(4)² + 3(4)] - [3³/3 - 2(3)² + 3(3)]

= 4/3 - 0

= 4/3 or 1⅓ or 1.33 units²