ЁЯУв Too many exams? DonтАЩt know which one suits you best? Book Your Free Expert ЁЯСЙ call Now!

    Question

    If 7sin²θ + 3cos²θ = 4, then find

    the value of θ?
    A 20┬░ Correct Answer Incorrect Answer
    B 30┬░ Correct Answer Incorrect Answer
    C 45┬░ Correct Answer Incorrect Answer
    D 55┬░ Correct Answer Incorrect Answer

    Solution

    7sin²θ + 3cos²θ = 4sin²θ + 3sin²θ+3cos²θ = 4 4sin²θ + 3(sin²θ + cos²θ) = 4 4sin²θ + 3 (1) = 4 4sin²θ = 4 - 3 = 1 4sin²θ = 1 sin²θ = 1/4 → sinθ = 1/2 sin30° = 1/2 Hence, θ = 30°

    Practice Next
    More Trigonometry Questions

    Relevant for Exams:

    ask-question