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Anonymous
Anonymous asked in Science & MathematicsMathematics Β· 1 month ago

find the exact value of cos (5pi/12)+cos(pi/12)?

i have to show work too!!

3 Answers

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  • Ash
    Lv 7
    1 month ago

    cos (5πœ‹/12) + cos(πœ‹/12)

    = 2 cos {[(5πœ‹/12) + (πœ‹/12)]/2} cos{[(5πœ‹/12) - (πœ‹/12)]/2}

    = 2 cos (πœ‹/4) cos (πœ‹/6)

    = 2 *(1/√2) *(√3)/2

    = √(3/2)

  • rotchm
    Lv 7
    1 month ago

    Hint: First, finish your past recent questions. That's just good netiquette and how you will learn.Β 

  • 1 month ago

    cos (5pi/12) + cos (pi/12)

    = (sqrt(3) - 1)/(2 sqrt(2)) + (1 + sqrt(3))/(2 sqrt(2))

    = sqrt(6)/2

    = 1.224744871391589049098642037352945695982973...

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