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Integral of 1/(a + b cos 2x) or 1/(a + b sin^2 x): divide by cos^2 x and substitute t = tan x

This type of question, asked 5 times: 2 May 2023 S1, 15 May 2023 S1, 25 Apr 2025 S1, 19 Apr 2026 S1, 13 May 2026 S1. All 5 questions below, oldest first.

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  1. Question 1

    2 May 2023 S1

    147
    ∫dx3−2cos⁡2x=tan⁡−1(f(x))5+c\displaystyle\int \dfrac{dx}{3 - 2\cos 2x} = \dfrac{\tan^{-1}(f(x))}{\sqrt{5}} + c, (where cc is constant of integration), then f(π/4)f(\pi/4) has the value

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  2. Question 2

    15 May 2023 S1

    105
    If ∫dx1+3sin⁡2x=12tan⁡−1(f(x))+c\int \frac{dx}{1+3\sin^{2}x} = \frac{1}{2}\tan^{-1}(f(x))+c, where c is a constant of integration, then f(x)f(x) is equal to

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  3. Question 3

    25 Apr 2025 S1

    122
    ∫dx3cos⁡2x+5\int\frac{dx}{3\cos2x+ 5} equals

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  4. Question 4

    19 Apr 2026 S1

    78
    The value of integral ∫dxsin⁡2x+tan⁡2x\displaystyle\int\dfrac{dx}{\sin^2 x + \tan^2 x} is...

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  5. Question 5

    13 May 2026 S1

    79
    The value of the integral ∫dx3+sin⁡2x+sin⁡2x=…\displaystyle\int\dfrac{dx}{3 + \sin 2x + \sin^2 x} = \ldots

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