Help with AQA core 4 integration (AQA spec)

Basically I have found some integration practice questions on the internet but they have conveniently failed to provide the answers. I am confident on most of them that I have go the correct answer however there are a few which I'm unsure on. So I was hoping the lovely people of the student room could help out, I've provided all my working too, so could you please tell me where I've gone wrong in these questions.

Thanks :smile:

Note: I've circled the questions in red because they can be well hidden and underlined my answers in red.

Please help XD

Thanks :smile:

Reply 1

davros

16

Original post by Zozzy

Basically I have found some integration practice questions on the internet but they have conveniently failed to provide the answers. I am confident on most of them that I have go the correct answer however there are a few which I'm unsure on. So I was hoping the lovely people of the student room could help out, I've provided all my working too, so could you please tell me where I've gone wrong in these questions.

Thanks :smile:

Note: I've circled the questions in red because they can be well hidden and underlined my answers in red.

Please help XD

Thanks :smile:

About to go offline now, but for the very first one, note that

\int e^u du = e^u + C

- you seem to have introduced an extra factor of 1/u in your answer!

Reply 2

Zozzy

OP

2

Original post by davros

About to go offline now, but for the very first one, note that

\int e^u du = e^u + C

- you seem to have introduced an extra factor of 1/u in your answer!

Ah thanks I can see the silly mistake now thanks :smile:

Reply 3

user2020user

16

Original post by Zozzy

Spoiler

2 and 4 are fine, but 3 has some problems. You've made a bunch of arithmetical mistakes like multiplying things by negative 1 that don't need to be multiplied by negative 1.

It might be a bit easier to completely transform your integral from