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Size:  494.7 KB help with this question pls. working and explanation please..
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    (Original post by Snowie9)
    help with this question pls. working and explanation please..
    Let a equal the radius. You can work out the sector area of COB by applying the formula from C2. We can call this area X.

    Next we need to find the area of the minor segment cut off by AC. We can apply the same formula with the angle being \pi-\theta and find the area of the sector COA, lets call this area Y. In order to find the minor segment area, we need to subtract the area of the triangle away from the sector. You can work out the area of the triangle from the formula involving sine, call this area T. Do Y-T to get your minor segment. Once you have the area of the minor segment, let's call it Z, you can say that Z=2X from the information you are given.

    The a's should cancel everywhere and you should rearrange to get your required answer. Remember that sin(\pi-\theta)=sin(\theta)
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    Well, what have you tried? What are your thoughts? Anything?
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    My result was pie - delta + sin delta = delta
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    (Original post by Snowie9)
    My result was pie - delta + sin delta = delta
    \pi is now 'pie' is it?

    But really, post your working out for us to check.
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    (Original post by Snowie9)
    My result was pie - delta + sin delta = delta
    Sounds like you're roughly on the right track, with a slip up somewhere. How'd you get that? (I can't read minds)
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    (Original post by Snowie9)
    I got (\pi-\theta) sin(\pi-\theta) = (\theta)
    Close. Show us your working out so I can see where you might've slipped up.
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    Name:  image.jpg
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Size:  496.6 KBThis is my working. Sorry I'm new to this website and I don't know how stuff works haha. By the way how do u type the pi ( sorry for the pie) symbols. thanks!!
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    (Original post by Snowie9)
    This is my working. Sorry I'm new to this website and I don't know how stuff works haha. By the way how do u type the pi ( sorry for the pie) symbols. thanks!!
    Don't worry about it. Very good work so far. Mistake on the last line. You have

    \displaystyle 

\begin{equation*} \frac{\pi}{2} - \frac{\theta}{2} + \frac{\sin \theta}{2} = \theta\end{equation*}

    Multiply everything by two:

    \displaystyle 

\begin{equation*} \pi - \theta + \sin \theta = 2\theta\end{equation*}

    Now add \theta to both sides.

    Your mistake was mutliplying the LHS by two but forgetting about the RHS, your factors of \frac{1}{2} disappeared without the \theta on the right changing to 2\theta,
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    (Original post by Snowie9)
    This is my working. Sorry I'm new to this website and I don't know how stuff works haha. By the way how do u type the pi ( sorry for the pie) symbols. thanks!!
    Last two lines; you forgot to multiply the right hand side by 2.

    To use mathematical writing on this site, refer here: http://www.thestudentroom.co.uk/wiki/LaTex
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    (Original post by Snowie9)
    11b, I can't seem to find the correct answer which is 53cm^2
    Again, working please.
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    (Original post by Snowie9)
    11b, I can't seem to find the correct answer which is 53cm^2
    Show us what you've tried.
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    omg thanks guys! didn't notice about my mistake on that.. thankssss😄😄
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    (Original post by Snowie9)
    omg thanks guys! didn't notice about my mistake on that.. thankssss😄😄
    No worries. It was just a silly mistake, happens to everybody.
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