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    How would you expand (1-x^2)^1/2 ?
    It doesn't seem to fit into either of the forms as n isn't a positive integer and the x is squared
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    (Original post by G.Y)
    How would you expand (1-x^2)^1/2 ?
    It doesn't seem to fit into either of the forms as n isn't a positive integer and the x is squared
    When n is negative or a fraction, you do it differently:

    E.g. (1 + bx)^n

    1 + (bx)(n) + ((n)(n-1)(bx)^2)/2! + ((n)(n-1)(n-2)(bx)^3)/3! ...

    Tip: If the number inside the bracket is not 1 ( e.g. (2 + bx)^n), then take the number out to make the number inside one.

    E.g. (2 + bx)^n = 2^n (1 + bx/2)^n

    I did this about a month ago so not exactly experienced lol. But hope I helped!

    And btw, the x^2 in the question doesn't make a difference to the method I shown above.
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    (Original post by G.Y)
    How would you expand (1-x^2)^1/2 ?
    It doesn't seem to fit into either of the forms as n isn't a positive integer and the x is squared
    Either,

    in your expansion where you'd normally have x, you want to put x^2, or,


    Let y=x^2

    Then expand (1+y)^1/2

    And when you have your series, substitute x^2 for the y.
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    (Original post by ghostwalker)
    Either,

    in your expansion where you'd normally have x, you want to put x^2, or,


    Let y=x^2

    Then expand (1+y)^1/2

    And when you have your series, substitute x^2 for the y.
    (Original post by C_Yap)
    When n is negative or a fraction, you do it differently:

    E.g. (1 + bx)^n

    1 + (bx)(n) + ((n)(n-1)(bx)^2)/2! + ((n)(n-1)(n-2)(bx)^3)/3! ...

    Tip: If the number inside the bracket is not 1 ( e.g. (2 + bx)^n), then take the number out to make the number inside one.

    E.g. (2 + bx)^n = 2^n (1 + bx/2)^n

    I did this about a month ago so not exactly experienced lol. But hope I helped!

    And btw, the x^2 in the question doesn't make a difference to the method I shown above.
    So the x^2 changes nothing? Thanksssss
 
 
 
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