Hey there! Sign in to join this conversationNew here? Join for free

Difference between minimum points and values of a parabola (C1) Watch

    • Thread Starter
    Offline

    8
    ReputationRep:
    Hi .

    I am answering the below past exam question.
    Name:  C1 question.png
Views: 69
Size:  79.3 KB

    For part (b) I have found the minimum point to be (1.5, 1.75) or in fractional form (3/2, 7/4).

    The answer says it is just 1.75

    I don't understand how this is the minimum value. I would get if it asked for the minimum y value but I am stumped as to why it would not be 1.5 (the x-value as it is lower).

    Could someone please clear this up?

    Thanks
    Offline

    15
    ReputationRep:
    The minimum value of a curve  y=f(x) is the minimum y coordinate of the curve.
    You can put in any (real) value of x you want, but you cannot possibly make the curve y have a value below 7/4 as you said (for real x).
    • Thread Starter
    Offline

    8
    ReputationRep:
    (Original post by B_9710)
    The minimum value of a curve  y=f(x) is the minimum y coordinate of the curve.
    You can put in any (real) value of x you want, but you cannot possibly make the curve y have a value below 7/4 as you said (for real x).
    Ah thanks, that makes sense.
    Offline

    3
    ReputationRep:
    The minimum value for x might be 1.5, but since it's asking you about the expression f(x), then you need to give the minimum value for f(x)

    The curve is y = f(x), so your y-coordinate would be the minimum value you'd want.
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Would you like to hibernate through the winter months?
    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
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • 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.