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    Hey guys,

    Please could someone be kind enough to help me with the question in the attachment. Any help will be appreciated.
    Thanks
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    my head hurts now..
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    (Original post by Aty100)
    Hey guys,

    Please could someone be kind enough to help me with the question in the attachment. Any help will be appreciated.
    Thanks
    Surely you've learnt function transformations? This is just of \cos x shift by \frac{\pi}{2} radians to the right. It will have the same minimum and maximum values as \cos x but the x coordinates of these extrema will be shift to the right as well. As will the roots.
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    Just derive it and set y' = 0
    Edit: rip answer
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    (Original post by GUMI)
    Just derive it and set y' = 0
    Edit: rip answer
    Heads up: you mean differentiate, not derive. :-)
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    f(x + a) --> translates graph horizontally by -a

    apply that to your situation?
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    (Original post by Zacken)
    Heads up: you mean differentiate, not derive. :-)
    Thanks, and I didn't know we were talking about transformations, woops x)
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    (Original post by GUMI)
    Thanks, and I didn't know we were talking about transformations, woops x)
    You can do it your way as well.
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    (Original post by Zacken)
    Surely you've learnt function transformations? This is just of \cos x shift by \frac{\pi}{2} radians to the right. It will have the same minimum and maximum values as \cos x but the x coordinates of these extrema will be shift to the right as well. As will the roots.
    I actually haven't learnt function transformations I did have a lesson the graphs but not any transformations. I'm not sure why the teachers skipped that :/
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    (Original post by Aty100)
    I actually haven't learnt function transformations I did have a lesson the graphs but not any transformations. I'm not sure why the teachers skipped that :/
    That's very weird. Anyhow, \cos(x - \frac{\pi}{2}), why don't you let y = x - \frac{\pi}{2} and then all you have is \cos y which you know how to find the roots of, the maximum and minimum, etc... once you've got all of those, then just back-substitute.
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    (Original post by Zacken)
    That's very weird. Anyhow, \cos(x - \frac{\pi}{2}), why don't you let y = x - \frac{\pi}{2} and then all you have is \cos y which you know how to find the roots of, the maximum and minimum, etc... once you've got all of those, then just back-substitute.
    Thank you, I understand that bit now. However do I change the limits for part iii) ?
    And if we do then does it become 0 + pi/2 < X < 2pi + pi/2 ??
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    (Original post by Aty100)
    Thank you, I understand that bit now. However do I change the limits for part iii) ?
    And if we do then does it become 0 + pi/2 < X < 2pi + pi/2 ??
    Yes. :yes:
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    (Original post by Zacken)
    Yes. :yes:
    Yay, thank you
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    (Original post by Aty100)
    Yay, thank you
    Don't thank me, you did it all by yourself, well done!
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    (Original post by Zacken)
    You can do it your way as well.
    hehe
 
 
 
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