📢 Too many exams? Don’t know which one suits you best? Book Your Free Expert 👉 call Now!

    Question

    What is the simplified value of the given

    expression? 4(sin² 20° + sin² 70°) + 2sin 30° - (2sec 60° + cot 45°)
    A 1 Correct Answer Incorrect Answer
    C 3 Correct Answer Incorrect Answer
    D -1 Correct Answer Incorrect Answer

    Solution

    4(sin ² 20° + sin ² 70°) + 2sin 30° - (2sec 60° + cot 45°)
    Using, sin(90° - A) = cos A
    = 4{sin ² 20° + sin ² (90 - 20)°} + 2 x 1/2 - {2 x 2 + 1}
    = 4(sin ² 20° + cos ² 20°) + 1 – 5
    Using, sin ² A + cos ² A = 1
    = 4 x 1 + 1 - 5 = 4 + 1 - 5 = 0

    Practice Next
    More Trigonometry Questions