New Enroll in RBI Grade B New Batch - Starts on May 21

    Question

    [(sinx – 2sin 3 x)/(2cos 3 x –

    cosx)] 2  + 1, x ≠45 o , is equal to:
    A coscec² x Correct Answer Incorrect Answer
    B sec²x Correct Answer Incorrect Answer
    C cot²x Correct Answer Incorrect Answer
    D 2tan²x Correct Answer Incorrect Answer

    Solution

    [(sinx – 2sin 3 x)/(2cos 3 x – cosx)] 2  + 1
    = [sinx(1 – 2sin 2 x)/cosx(2cos 2 x – 1)] 2  + 1 = [tanx(cos2x)/(cos2x)] 2  + 1 = tan 2 x + 1
    = sec 2 x

    Practice Next