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Math Help - quick help with quadrants

  1. #1
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    quick help with quadrants

    i have a problem that is:

    directions:
    "Let theta be an angle in standard position. In which quadrant or quadrants can theta lie under the given conditions?"

    Sin theta and tan theta have the same sign.

    Can someone who answers this also explain how to do this problem? I have a unit circle graph but have no idea how to use it.... ty in advance
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  2. #2
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    Quote Originally Posted by d1338 View Post
    i have a problem that is:

    directions:
    "Let theta be an angle in standard position. In which quadrant or quadrants can theta lie under the given conditions?"

    Sin theta and tan theta have the same sign.

    Can someone who answers this also explain how to do this problem? I have a unit circle graph but have no idea how to use it.... ty in advance
    Hi d1338,

    tan\theta=\frac{sin\theta}{cos\theta}

    hence, an easy way to look at this is....

    sin\theta and tan\theta have the same sign only when cos\theta is positive.

    Hence, you need to know where cos\theta is positive, which occurs for angles to the right of the y-axis.
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    Quote Originally Posted by d1338 View Post
    i have a problem that is:

    directions:
    "Let theta be an angle in standard position. In which quadrant or quadrants can theta lie under the given conditions?"

    Sin theta and tan theta have the same sign.

    Can someone who answers this also explain how to do this problem? I have a unit circle graph but have no idea how to use it.... ty in advance
    quad I ... sin and cos both (+)

    quad II ... sin(+) , cos(-)

    quad III ... sin and cos both (-)

    quad IV ... sin(-), cos(+)

    note that tangent is the ratio of sine/cosine
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    MHF Contributor harish21's Avatar
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    Quote Originally Posted by d1338 View Post
    i have a problem that is:

    directions:
    "Let theta be an angle in standard position. In which quadrant or quadrants can theta lie under the given conditions?"

    Sin theta and tan theta have the same sign.

    Can someone who answers this also explain how to do this problem? I have a unit circle graph but have no idea how to use it.... ty in advance




    This is how I learnt:
    Remember ASTC : Add Sugar To Coffee

    A: 1st quadrant: All identities are positive
    S: 2nd quadrant: only sine is positive
    T: 3rd quadrant: only tan is positive
    C: 4th quadrant: only cosine is positive
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    All silver tea cups
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