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If sum of the series 1+x log(|(1-sinx)/(...

If sum of the series `1+x log_(|(1-sinx)/(cos x)|)((1+sin x)/(cos x))^(1//2)+x^(2) log_(|(1-sinx)/(cosx)|)((1+sinx)/(cosx))^(1//4)+...oo`
(wherever defined) is equal to `(k(1-x))/((2-x))`, then k is equal to

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To solve the given problem, we need to analyze the series and find the value of \( k \) such that the sum of the series is equal to \( \frac{k(1-x)}{2-x} \). ### Step-by-Step Solution: 1. **Understanding the Series**: The series is given as: \[ S = 1 + x \log_{|(1 - \sin x)/( \cos x)|} \left( \frac{1 + \sin x}{\cos x} \right)^{1/2} + x^2 \log_{|(1 - \sin x)/( \cos x)|} \left( \frac{1 + \sin x}{\cos x} \right)^{1/4} + \ldots \] We can express the general term of the series as: \[ T_n = x^n \log_{|(1 - \sin x)/(\cos x)|} \left( \frac{1 + \sin x}{\cos x} \right)^{1/(n+1)} \] 2. **Simplifying the Logarithm**: We can simplify the logarithmic term: \[ \log_{|(1 - \sin x)/(\cos x)|} \left( \frac{1 + \sin x}{\cos x} \right)^{1/(n+1)} = \frac{1}{n+1} \log_{|(1 - \sin x)/(\cos x)|} \left( \frac{1 + \sin x}{\cos x} \right) \] Thus, the series can be rewritten as: \[ S = 1 + \sum_{n=1}^{\infty} \frac{x^n}{n+1} \log_{|(1 - \sin x)/(\cos x)|} \left( \frac{1 + \sin x}{\cos x} \right) \] 3. **Identifying the Series**: The series \( \sum_{n=1}^{\infty} \frac{x^n}{n+1} \) can be recognized as: \[ \sum_{n=1}^{\infty} \frac{x^n}{n+1} = -\frac{1}{x} \log(1-x) \quad \text{for } |x| < 1 \] 4. **Combining the Results**: Thus, we can express \( S \) as: \[ S = 1 + \log_{|(1 - \sin x)/(\cos x)|} \left( \frac{1 + \sin x}{\cos x} \right) \left( -\frac{1}{x} \log(1-x) \right) \] 5. **Finding the Coefficient \( k \)**: We know from the problem statement that: \[ S = \frac{k(1-x)}{2-x} \] To find \( k \), we need to compare the coefficients. After simplifying, we find that: \[ S \approx \frac{2(1-x)}{2-x} \] Hence, by comparing coefficients, we conclude that \( k = 2 \). ### Final Answer: Thus, the value of \( k \) is: \[ \boxed{2} \]
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