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# How do I integrate (e^x)(Cosx)dx? Watch

1. I need help with the above questions please guys! Thanks! =)
2. (Original post by Delta, Δ)
I need help with the above questions please guys! Thanks! =)
Integrate by parts.
3. I don't Think integration by parts will work since you end up vetting the integral of e^xsinx at some point.

If you are familiar with demoivres theorem then that Is one way. I'd be surprised if they gave that question in a normal core paper without external help.
4. You do it by parts.

Let I = e^x cosx

And solve for I
5. (Original post by BankOfPigs)
I don't Think integration by parts will work since you end up vetting the integral of e^xsinx at some point.

If you are familiar with demoivres theorem then that Is one way. I'd be surprised if they gave that question in a normal core paper without external help.
Wolfram Alpha says integration by parts. There's a trick to it though.
6. (Original post by rayquaza17)
Wolfram Alpha says integration by parts. There's a trick to it though.
I quite like the idea of recurring integrals.
7. Honestly, integration by parts: (Check spoiler after you have done integration by parts 1 time):

Spoiler:
Show

What do you get when you preform integration by parts on ?

Is there anyway to simplify the expression we now have for ?
8. (Original post by BankOfPigs)
I don't Think integration by parts will work since you end up vetting the integral of e^xsinx at some point.

If you are familiar with demoivres theorem then that Is one way. I'd be surprised if they gave that question in a normal core paper without external help.
This is a standard A level integration by parts question - no need for de Moivre. At some point you get an expression for your original integral in terms of itself, then you just rearrange and solve.
9. (Original post by davros)
This is a standard A level integration by parts question
I'm not sure about other Awarding Bodies but it was removed from the OCR specification over a decade ago. The endorsed textbook includes it as an asterixed question (beyond the scope of the course).
10. In a way I do wish the boards would state the exam specification simply in terms of a huge list of questions the candidate needs to be able to answer.
11. (Original post by Mr M)
I'm not sure about other Awarding Bodies but it was removed from the OCR specification over a decade ago. The endorsed textbook includes it as an asterixed question (beyond the scope of the course).
I await the day when quadratics with imaginary roots are considered beyond the scope of the course.
12. (Original post by Mr M)
I'm not sure about other Awarding Bodies but it was removed from the OCR specification over a decade ago. The endorsed textbook includes it as an asterixed question (beyond the scope of the course).
I was talking about 'real' A levels - not this silly modular nonsense

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