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Math Help - Identity Help

  1. #1
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    Identity Help

    If we establish an identity, -sinAcscA - sin^(2)A - cos^(2)A - tanAcotA would equal....

    does it equal 3cos^(2)A - 1 or 3cos^(2)A - 2sin^(2)A?
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  2. #2
    Forum Admin topsquark's Avatar
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    Quote Originally Posted by andy11 View Post
    If we establish an identity, -sinAcscA - sin^(2)A - cos^(2)A - tanAcotA would equal....

    does it equal 3cos^(2)A - 1 or 3cos^(2)A - 2sin^(2)A?
    Who gave you the possible answers for this?
    -sin(A) \cdot csc(A) - sin^2(A) - cos^2(A) - tan(A) \cdot cot(A)

    - sin(A) \cdot \frac{1}{sin(A)} - (sin^2(A) + cos^2(A)) - tan(A) \cdot \frac{1}{tan(A)}

    -1 - (1) - 1 = -3

    I smell a typo somewhere...

    -Dan
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  3. #3
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    yeah your right.. i just checked with a friend.. i messed up on the first step.. thanks
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  4. #4
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by topsquark View Post
    Who gave you the possible answers for this?
    -sin(A) \cdot csc(A) - sin^2(A) - cos^2(A) - tan(A) \cdot cot(A)

    - sin(A) \cdot \frac{1}{sin(A)} - (sin^2(A) + cos^2(A)) - tan(A) \cdot \frac{1}{tan(A)}

    -1 - (1) - 1 = -3

    I smell a typo somewhere...

    -Dan
    that's what I got and i thought i was missing something. But since you got the same thing, I guess I was right
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