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    Hey

    I'm currently revising for Edexcel GCSE Higher Mathematics and i've come upon the section of Trigonometry of Any Angle.

    I've memorised the periodic graphs of Y = SIN X, Y = COS X and Y = TAN X, however has anyone got any extra information which could help me? Such as the asymptotes and other parts please.

    On the other section is a part on "Angles of Any Size", which includes such questions as "Find 6 different angles x such that sin x = 0.94" or "Find three other angles which have the same cosine as 65". Also there are some questions on solving for trigonometric equations plus a question which involves a circle being split into 4 equal quadrants.

    I was wondering can someone please help me with the things which I am doing by offering some information and GCSE's websites which could help me? Many thanks and I very much appreciate all comments posted
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    cosx=cos(x+2n\pi), \ cosx=cos(2\pi-x)

    sinx=sin(x+2n\pi), \ sinx=sinx(\pi-x)

    tanx=tan(x+n\pi)
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    Hey Will they allow me to calculate the trigonometric equations? But would I lose marks considering that they may want working out from graphs?
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    (Original post by nick198929)
    Hey Will they allow me to calculate the trigonometric equations? But would I lose marks considering that they may want working out from graphs?
    The above equations can be derived by use of graphs. But its always safe to draw graphs in an exam nevertheless.

    For example, using the first equation, cos0.41 = cos(2\pi-0.41) = cos(2\pi+0.41) = cos(4\pi-0.41) = cos(4\pi+0.41)...

    You see?
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    (Original post by sohanshah)
    The above equations can be derived by use of graphs. But its always safe to draw graphs in an exam nevertheless.

    For example, using the first equation, cos0.41 = cos(2\pi-0.41) = cos(2\pi+0.41) = cos(4\pi-0.41) = cos(4\pi+0.41)...

    You see?
    Yes GCSE examiners are always delighted when pupils work in radians.
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    Brilliant thanks. So for example, Find 6 different angles x such that sin x = 0.94

    Would that then be Sin x = sin (x + 2pi) so SIN X = SIN (0.94 + 2 X 3,141592654) ?
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    (Original post by nick198929)
    Brilliant thanks. So for example, Find 6 different angles x such that sin x = 0.94

    Would that then be Sin x = sin (x + 2pi) so SIN X = SIN (0.94 + 2 X 3,141592654) ?
    On your calculator type shift sin 0.94

    The answer is 70.1 degrees - this is the principal solution.

    To find five other angles, just add on multiples of 360 degrees.
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    Thanks alot Mr M. But i was wondering in the question, Find 6 different angles x such that sin x = 0.94.

    How does that information fit into the equation of Sin x = sin (x + 2pi) ?

    Many thanks
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    (Original post by nick198929)
    Thanks alot Mr M. But i was wondering in the question, Find 6 different angles x such that sin x = 0.94.

    How does that information fit into the equation of Sin x = sin (x + 2pi) ?

    Many thanks
    The identity above uses radian measure instead of degrees. 2pi radians is one complete turn, the same as 360 degrees. Work in degrees if you want to get any marks.
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    Ok kk. Thanks alot, Mr M
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    (Original post by nick198929)
    Ok kk. Thanks alot, Mr M
    You are welcome.
 
 
 
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