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    Dear Maths genius,

    I have a problem in this question. it asks to write the coordinates of any point that meets the axes. but in this example and in the other exercises in EXERCISE 5B c3 (edexcel). The examiner in the solution does not inlcude (0,0) if the curve cuts it. Why is this?

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    (Original post by bigmansouf)
    Dear Maths genius,

    I have a problem in this question. it asks to write the coordinates of any point that meets the axes. but in this example and in the other exercises in EXERCISE 5B c3 (edexcel). The examiner in the solution does not inlcude (0,0) if the curve cuts it. Why is this?

    thank you very much
    They do, (0,0) is the origin labelled O and since it's sine that isn't translated anywhere then it's just common sense to know that it WILL go through O without any explicit explanation needed.
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    (Original post by RDKGames)
    They do, (0,0) is the origin labelled O and since it's sine that isn't translated anywhere then it's just common sense to know that it WILL go through O without any explicit explanation needed.
    so if i was to mention that it goes through (0,0) i will not get the answer error in an exam or any marks taken away

    I am more worried about this as i dont want any silly mistakes on my part

    i hope you understand
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    (Original post by bigmansouf)
    so if i was to mention that it goes through (0,0) i will not get the answer error in an exam or any marks taken away

    I am more worried about this as i dont want any silly mistakes on my part

    i hope you understand
    No you will not be marked down because it IS a solution and you can even prove it. Unless they specifically say all the solutions in the range except (0,0) which may expect.

    (0,0) would perhaps be considered a trivial solution where it's obvious that the curve goes through that point so really you can just say (0,0) without any working, but if your're working includes general solutions to sine then (0,0) will show up as a solution anyway just to confirm it.
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    (Original post by RDKGames)
    No you will not be marked down because it IS a solution and you can even prove it.

    (0,0) would perhaps be considered a trivial solution where it's obvious that the curve goes through that point so really you can just say (0,0) without any working, but if your're working includes general solutions to sine then (0,0) will show up as a solution anyway just to confirm it.
    thank you for your time to answer my trivial question
    but i mae silly mistakes in my test for my self so i kinda worried about everything
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    When a curve cuts the x axis, it crosses the x axis rather than touches the x axis. The term 'cut' is well defined here, the curve  y=x^2 touches te x axis at (0, 0) but it certainly does not cut the x axis. A curve cuts the x axis if there is a point, say point A with coordinates (a, 0), such that  f(a+\epsilon )\cdot f(a-\epsilon ) <0, \ \epsilon >0 where  \epsilon is a small real number. The curve has to be above the x axis at one point and above it at another point either side of the root to be said to cut the x axis.
 
 
 
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