Edexcel 2019 paper 1 8c integration

[warped geyser]

8c doesn’t make sense to me I don’t understand the markscheme either
Can someone please explain?

[opal cradle]

So if you take the above x axis the integral is the same as you taking the integral from 0 to 4

The two regions that are above the x axis will be the same as the one below

Is like a symmetry

[onyx crane]

Can u explain it again I don’t really understand aswel part c

[opal cradle]

right so when you integrate to 1.25 you get a negative area, if you integrate to 5.25 smth, it will take consideration to the negative area

with these two markers they will be a simple statement

so that is why the area of negative equals to 20/3

they are the same

but the other side is negative

[warped geyser]

I still can’t grasp the concept I don’t get how u would just know by looking at it

[stone rampart]

same