Turn on thread page Beta
    • Thread Starter
    Offline

    14
    ReputationRep:
    \displaystyle\int_1^2\ -4x^5} = \left[ \frac{ -4x^6}{6}\right]_1^2

    just wondering what the next step would be

    i guess it would be -x^6 on top of the next fraction, but i dunno about on the bottom?
    Offline

    0
    ReputationRep:
    What...?

    Do you want to evaluate the integral because you are effectively there...
    Offline

    14
    If you have \displaystyle \left[ \text{stuff} \right]^a_b then you do \text{stuff(a) - stuff(b)}.

    So it's \dfrac{-4}{6} \times 2^6 - (\dfrac{-4}{6} \times 1^6).
    • Thread Starter
    Offline

    14
    ReputationRep:
    (Original post by Jimny)
    What...?

    Do you want to evaluate the integral because you are effectively there...
    complete the following integrations, it says

    i'm a maths noob :p: :o:
    Offline

    14
    (Original post by robinson999)
    complete the following integrations, it says

    i'm a maths noob :p: :o:
    Ah. Well, that general rule is:

    \displaystyle \int x^n = \frac{x^{n+1}}{n+1} (for n not equal to 1).

    In your case n = 5, so insert this into the formula, remembering the multiplier of 4 and then use my post above.

    Maths repulses me.
    • Thread Starter
    Offline

    14
    ReputationRep:
    i think i get it, i don't think my lecture notes help at all
    can't see where the other numbers came from in the example they use

    \dfrac{-4}{6} \times 2^6 - (\dfrac{-4}{6} \times 1^6)

    would they just come out as -42?
    or 64
    i'll take -42 as the post below says :p:
    Offline

    12
    ReputationRep:
    yep
    Offline

    15
    ReputationRep:
    (Original post by Glutamic Acid)
    Ah. Well, that general rule is:

    \displaystyle \int x^n = \frac{x^{n+1}}{n+1} (for n not equal to 1).

    In your case n = 5, so insert this into the formula, remembering the multiplier of 4 and then use my post above.

    Maths repulses me.
    GA do you know how to derive it? I know it should involve Riemann sum notation.
    Offline

    14
    (Original post by Simplicity)
    GA do you know how to derive it? I know it should involve Riemann sum notation.
    I can do it using inequalities (there was an old question on find x^5; it could be easily generalized for x^n), not sure about Riemann sum notation, though. [Actually, the aforementioned question is a definite integral between 0 and 1, but I think that's fixable.]
    • Wiki Support Team
    Offline

    14
    ReputationRep:
    Wiki Support Team
    (Original post by Glutamic Acid)
    (for n not equal to 1)
    *stabs*

    n not equal to -1.
    Offline

    14
    (Original post by generalebriety)
    *stabs*

    n not equal to -1.
    Oh, oops. :o:

    (+1)
 
 
 
Poll
Is the Big Bang theory correct?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.