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C3 maths question - differentiate to find a stationary point Watch

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    Hi, I'm stuck on this question:

    Q. The curve with equation y = 1/(x^2 + 1) has a single stationary point A. Find the coordinates of A.

    ... so I've differentiated the equation which gives dy/dx = (-2x)/(x^2 +1)^2
    then I've made that equal to 0, but I'm not sure how you go on to solve it because I don't think you can just multiply up because the 0 would just cancel it out?

    Thanks for any help!

    (the answer is (0,1) by the way, but idk why)
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    (Original post by daisy18000)
    Hi, I'm stuck on this question:

    Q. The curve with equation y = 1/(x^2 + 1) has a single stationary point A. Find the coordinates of A.

    ... so I've differentiated the equation which gives dy/dx = (-2x)/(x^2 +1)^2
    then I've made that equal to 0, but I'm not sure how you go on to solve it because I don't think you can just multiply up because the 0 would just cancel it out?

    Thanks for any help!

    (the answer is (0,1) by the way, but idk why)
    The numerator must be 0 for a fraction to be equal to 0. So you're solving 2x=0
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    (Original post by B_9710)
    The numerator must be 0 for a fraction to be equal to 0. So you're solving 2x=0
    Ahh okay that makes sense. Thank you.
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    Nothing worse than doing all that hard work only to end up with x=0
 
 
 
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