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Math Help - Find all the solutions (Inverse Trig Funct.)

  1. #1
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    Find all the solutions (Inverse Trig Funct.)

    5 cos (x + 3) = 1

    Need steps or directions please.

    Thank you!
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  2. #2
    Junior Member
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    Treat it like a regular algebra problem.

    Here's a hint, there will be division and an inverse function.
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  3. #3
    Junior Member
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    1. Divide 5
    2. Arc Cosine
    3. Subtract 3
    4. Answer is -1.63 (the first solution)

    However the solution page shows 1.914 and 4.653.
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  4. #4
    Super Member Bacterius's Avatar
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    5 \cos (x + 3) = 1

    \cos(x + 3) = \frac{1}{5}

    \arccos(\cos(x + 3)) = \arccos(\frac{1}{5})

    x + 3 = \arccos(\frac{1}{5})

    x = \arccos(\frac{1}{5}) - 3

    x \approx -1.63

    Yeah ... there's something not right there, are you sure you checked the right solutions against the exercise ?
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