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Math Help - Triangle and Trignometry Help

  1. #1
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    Triangle and Trignometry Help

    How do I do:

    Show that for all x E (0, pi), the area of a triangle with side lengths a and b and with included angle x is A= 1/2(a)(b)(sin x) (Hint: You need to consider two cases.)



    and



    2sin^2 x - 5sin x + 3 < 0 in interval [0, 2pi)



    Can someone help me a bit please :P
    Thanks!
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  2. #2
    Senior Member
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    Hi mms6

    Question 1
    Draw a triangle. You have to consider x as acute angle and obtuse angle. Then, use formula :

    \text{Area} = \frac{1}{2}*\text{base}*\text{height}

    (Another hint : state the height in term of trigonometry)


    Question 2
    Factorize LHS then find the critical point

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  3. #3
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    thanks I understand the first question, but I am still unsure of the second question.
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  4. #4
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    Hi mms6

    Can you fatorise the LHS ? After that set LHS = 0 to find the critical point
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  5. #5
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    Um... What iss LHS exactly?

    Sorry for asking a kinda sad question I am not very good with math.
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  6. #6
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    Hi mms6

    LHS = left hand side
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