Core 1 (Edexcel)

Announcements Posted on
How helpful is our apprenticeship zone? Have your say with our short survey 02-12-2016
    • Thread Starter
    Offline

    0
    ReputationRep:
    For what value of n is X the smallest
    x=(n-5)^2 +2
    Offline

    3
    ReputationRep:
    5?
    Offline

    1
    ReputationRep:
    (Original post by reb0xx)
    For what value of n is X the smallest
    x=(n-5)^2 +2
    Differentiate the expression with respect to n, and set the derivative equal to zero.

    Or you can also just notice the value by looking at the equation.

    By the way, why is the thread label undergraduate?
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by raheem94)
    Differentiate the expression with respect to n, and set the derivative equal to zero.

    Or you can also just notice the value by looking at the equation.

    By the way, why is the thread label undergraduate?
    Ok thank you but what if there are two values of 0
    from maximun and minimum
    Offline

    1
    ReputationRep:
    (Original post by reb0xx)
    Ok thank you but what if there are two values of 0
    from maximun and minimum
    I am not understanding your question.

    You differentiate, and set the derivative equal to zero to find the values, then consider which value is max and which is min by finding the second derivative.
    Offline

    2
    ReputationRep:
    (Original post by raheem94)
    I am not understanding your question.

    You differentiate, and set the derivative equal to zero to find the values, then consider which value is max and which is min by finding the second derivative.
    This question is clearly not meant for differentiation. Plus it'd be a lot more effort (at least for a Core 1 student as they'd need to multiply the bracket out then differentiate).



    OP; you should have learnt how to find the minimum value (vertex) of a quadratic using completing the square. This is that.
    Offline

    2
    ReputationRep:
    (Original post by Earnest Moore)
    n=(5+∞i)
    2 posts and you're trolling -.-
    Offline

    0
    ReputationRep:
    (Original post by hassi94)
    2 posts and you're trolling -.-
    How is that trolling?

    Please, point out if I made a mistake.
    Offline

    1
    ReputationRep:
    (Original post by hassi94)
    This question is clearly not meant for differentiation. Plus it'd be a lot more effort (at least for a Core 1 student as they'd need to multiply the bracket out then differentiate).



    OP; you should have learnt how to find the minimum value (vertex) of a quadratic using completing the square. This is that.
    The thread label is 'undergraduate', so the OP should be knowing this mate.

    I didn't understood what the OP was saying, so i recommended him to differentiate, the chapters may vary by boards, in edexcel i don't think they will give min max questions in C1, though i am not sure.

    At this time of the year, the OP would have probably done C2 as well, so i think he might be knowing it.
    Offline

    0
    ReputationRep:
    (Original post by Earnest Moore)
    How is that trolling?

    Please, point out if I made a mistake.
    

(n-5)^2 \geq 0

(n-5)^2 + 2 \geq 2

x \geq 2
    Hence least value of x is 2, which occurs when n=5.
    Offline

    0
    ReputationRep:
    It's valid. No conditions were specified.

    if;
    

n \in \mathbb{R}
    then fair enough, but that wasn't stated.
    Offline

    2
    For the sake of not confusing the OP, and to prevent the thread from descending into a flamewar, I've removed a few posts which went in this direction.

    (Original post by Earnest Moore)
    It's valid. No conditions were specified.

    if;
    

n \in \mathbb{R}
    then fair enough, but that wasn't stated.
    It says in the thread title that this is a C1 problem, so it didn't really need to be stated; and even if not, your post wasn't correct.
 
 
 
Write a reply… Reply
Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. Oops, you need to agree to our Ts&Cs to register
  2. Slide to join now Processing…

Updated: May 9, 2012
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

Today on TSR
Poll
Would you rather have...?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read here first

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
Study resources

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

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