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What model calculator do you use for A level Maths? Watch

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    (Original post by Zacken)
    Do you mean quadratic formula? I think he knows that already.
    Yeah I meant quadratic formula. I know how to use that.

    But don't know how to use a calculator to work out what goes into the factorising brackets when factorising a quadratic.

    Is there even a way to use a calculator to do that?
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    (Original post by Philip-flop)
    Thanks guys. I know you can use a calculator to work out a quadratic equation using the quadratic formula but, is there a way of using a calculator to help factorise a quadratic equation? (Sorry if I sound like such a newbie, I'm a mature student and have only been learning A-level Maths since October but before this I hadn't studied Maths since I was at school 7 years ago!!)
    (Original post by Student403)
    Nope but here's an easy trick

    Let's say you get x = -1, x = 5/3

    All you have to do is rearrange to get 0 on one side, for each one

    First one would be easy
    (x+1) = 0

    Second one:

    x = 5/3
    3x = 5
    (3x - 5) = 0

    Then multiply the two together to get your factorised quadratic

    (x+1)(3x-5)=0
    (Original post by Zacken)
    If you put in a quadratic equation x^2 + bx + c = 0 into your calculator and it tells you that the roots/solutions are \alpha and \beta, then your quadratic is factorised as (x-\alpha)(x-\beta). If this sounds foreign to you, then let's try an example.

    We have x^2 -7x + 10 = 0, plug this into your calculator. Your calculator will show you that the roots are x=5 or x=2. This means that the quadratic factorises as (x-5)(x-2).
    It seems like you haven't seen these two posts, so just quoting them for you!
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    (Original post by Student403)
    It will give you x = -4/3, x = 2

    Not factorise
    Oh I see. How do you use a calculator to give you those 2 values of x though?
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    (Original post by Philip-flop)
    Oh I see. How do you use a calculator to give you those 2 values of x though?
    You mean how do you use a calculator to solve a quadratic?
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    http://youtu.be/ubztYMkI3fY
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    (Original post by Zacken)
    It seems like you haven't seen these two posts, so just quoting them for you!
    Ah yeah oops. I didn't see that person's comment that you quoted last.
    This is going to sound stupid but I'm not sure I actually know how to correctly type a quadratic equation into my calculator

    If possible, can someone send me a video?
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    (Original post by Philip-flop)
    Ah yeah oops. I didn't see that person's comment that you quoted last.
    This is going to sound stupid but I'm not sure I actually know how to correctly type a quadratic equation into my calculator

    If possible, can someone send me a video?
    Totally alright It's not something you should know

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    Thanks Student403.

    Everyone I've come to the conclusion that my calculator doesn't give me the "equation" function to work out quadratics like the video above think I may have to invest in a better calculator!!

    Do you think it's worth me getting a new calculator or shall I just carry on working out quadratics in my head as I have been doing for C2?
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    (Original post by Philip-flop)
    Thanks Student403.

    Everyone I've come to the conclusion that my calculator doesn't give me the "equation" function to work out quadratics like the video above think I may have to invest in a better calculator!!
    No problem

    I think you should, yeah. For the exams, a model similar to that would be ideal, especially with handy quadratic solvers if you're just getting back in to maths. What model is your current one?
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    (Original post by Student403)
    No problem

    I think you should, yeah. For the exams, a model similar to that would be ideal, especially with handy quadratic solvers if you're just getting back in to maths. What model is your current one?
    My current calculator is the CASIO fx-85GT PLUS

    I have AS Maths exams in the summer and am feeling rather nervous too
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    I have a Casio one that also does differentiation and integration, but only if you put in a value for x. It's very useful for checking that your answers are right and it's allowed because it won't give you a differentiated or integrated expression. The best one you're allowed in exams is a graphical calculator.


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    TI 83. Save all those nasty vector formulae in there
    Spoiler:
    Show
    But don't tell anyone :X
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    Casio fx-9860GII - brilliant. Does simultaneous equations up to 6 vars, polynomials up to the 6th degree, integration, differentiation, unit conversion... anything you'd want out of a calculator, really!
 
 
 
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