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    Is there a method of doing part (a) using  sin^2x + cos^2x = 1?
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    is this A-level maths?
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    (Original post by IgorYakov)
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    Is there a method of doing part (a) using  sin^2x + cos^2x = 1?
    None that I can think of, it's difficult to because this is inverse functions not the original functions. There's two methods that come to mind:

    1) y=arccosx
    cosy = x
    so arcsinx = arcsin(cosy)

    2) cosy=x
    so x=sin(pi/2 - y)
    so arcsinx = pi/2 - y
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    (Original post by studos)
    is this A-level maths?

    Yep it's from the Jan 07 paper, from the examiners report less than 10% could do this question


    (Original post by Mike_123)
    None that I can think of, it's difficult to because this is inverse functions not the original functions. There's two methods that come to mind:

    1) y=arccosx
    cosy = x
    so arcsinx = arcsin(cosy)

    2) cosy=x
    so x=sin(pi/2 - y)
    so arcsinx = pi/2 - y

    Yeah 2) is how it is in the mark scheme. Was just wondering, thanks!
 
 
 
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