Overview: 1 questions will be solved this time.Among them
           ☆1 inequalities

[ 1/1Inequality]
    Assignment:Find the solution set of inequality 80-10cos(πt/12) ≥78 .
    Question type: Inequality
    Solution:
    The inequality can be reduced to 1 inequality：
        80 - 10 * cos ( π * t / 12 ) ≥78         (1)

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    From inequality(1)：
         t ≤ -53.230869 或  -42.769131 ≤ t ≤ -29.230869 或  -18.769131 ≤ t ≤ -5.230869 或  5.230869 ≤ t ≤ 18.769131 或  29.230869 ≤ t ≤ 42.769131 或  t ≥ 53.230869

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    The final solution set is :
         t ≤ -53.230869 或  -42.769131 ≤ t ≤ -29.230869 或  -18.769131 ≤ t ≤ -5.230869 或  5.230869 ≤ t ≤ 18.769131 或  29.230869 ≤ t ≤ 42.769131 或  t ≥ 53.230869
    *Note: Radian.

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