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    I'm stumped on Q7d

    f(x) = 3x^2 + 6x + 3 -1<=x<=0
    0 Otherwise

    Find P (-0.3 < X < 0.3)

    I tried integrating between -0.3 and 0.3 but I get the wrong answer and i'm not sure why.

    Any help appreciated. Thanks!
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    it is F(0.3) - F(-0.3)
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    yeh the mark scheme says that but to be honest, im not sure what F(0.3) means or how u do it.
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    it means P(x<=0.3)

    all you have to do is bung in values in the formula for F(x) but note that
    F(0.3)= 1
    if you are integrating also use the fact that for all values greater than zero
    F(x)=1
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    (Original post by iaN^|Uno|)
    I'm stumped on Q7d

    f(x) = 3x^2 + 6x + 3 -1<=x<=0
    0 Otherwise

    Find P (-0.3 < X < 0.3)

    I tried integrating between -0.3 and 0.3 but I get the wrong answer and i'm not sure why.

    Any help appreciated. Thanks!
    Try integrating between -0.3 and 0, as x cannot be greater than 0.
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    thanks for the help! i didnt realise that x couldn't be greater than 0
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    (Original post by iaN^|Uno|)
    thanks for the help! i didnt realise that x couldn't be greater than 0
    It can be, but no point in including it as the probability is 0
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    does anyone have teh markscheme for this? pleeease! x
 
 
 
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