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Math Help - a little help please

  1. #1
    ck3
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    Question a little help please

    1. the angle A is standard position is defined in terms of the co-ordinates (x,y) of the terminal arm, and the radius r of the circle. the trigonometric functions of the angle A can be expressed in terms of x,y, and r. the expression r/x represents is?

    2. how many solutions are there to the equation sin^2 x + sin x = 0 over the domain.

    3. smallest positive angle that is equivalent to an angle of -2pi/3 is?
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  2. #2
    Grand Panjandrum
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    Quote Originally Posted by ck3 View Post
    1. the angle A is standard position is defined in terms of the co-ordinates (x,y) of the terminal arm, and the radius r of the circle. the trigonometric functions of the angle A can be expressed in terms of x,y, and r. the expression r/x represents is?
    This is a bit difficult to understand, but I will assume it describes the
    situation in the attachment.

    Then sec(A)=r/x=1/cos(A).

    RonL
    Attached Thumbnails Attached Thumbnails a little help please-gash.jpg  
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  3. #3
    Grand Panjandrum
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    Quote Originally Posted by ck3 View Post
    2. how many solutions are there to the equation sin^2 x + sin x = 0 over the domain.
    I assume by the domain you mean [0,2pi), we seek the points at which
    sin^2(x)=-sin(x). Plot these and count them. See attachment, I make
    it 3 (as the fourth is at 2pi which is outside the domain).

    3. smallest positive angle that is equivalent to an angle of -2pi/3 is?
    the required positive angle is 2pi-2pi/3=4pi/3.

    RonL
    Attached Thumbnails Attached Thumbnails a little help please-gash.jpg  
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