Question:medium

If for logcos x (cot x) - 4log(sin x) cot x = 1, x = sin-1 \((\frac{\alpha+\sqrt{\beta}}{2})\). Find (α + β), given x ∈ \((0,\frac{\pi}{2})\)

Updated On: Mar 12, 2026
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Correct Answer: 4

Solution and Explanation

To solve the problem, start with the equation: logcos x (cot x) - 4logsin x (cot x) = 1. Using properties of logarithms, the given equation can be rewritten:
\(\frac{log (cot x)}{log (cos x)} - 4 \cdot \frac{log (cot x)}{log (sin x)} = 1\).

Let y = log (cot x), then the equation simplifies to:
\(\frac{y}{log (cos x)} - \frac{4y}{log (sin x)} = 1\).
Factor out y:
y\left(\frac{1}{log (cos x)} - \frac{4}{log (sin x)}\right) = 1.
This implies:
y = \frac{1}{\frac{1}{log (cos x)} - \frac{4}{log (sin x)}}.
Now, notice that:
cot x = \frac{cos x}{sin x}, y = log(cos x) - log(sin x).
Substitute back:
\(\frac{log(cos x) - log(sin x)}{log (cos x)} - 4\cdot\frac{log(cos x) - log(sin x)}{log (sin x)} = 1\)
Simplifying gives:
\(\frac{log(cos x)}{log (cos x)} - \frac{log(sin x)}{log (cos x)} - \cdot4 + \frac{4log(sin x)}{log (sin x)} = 1\)
Results in:
1 - \frac{log(sin x)}{log (cos x)} - \cdot4 + 4 = 1\)
Solving for x in terms of sin-1 representation:
x = sin^{-1} \left(\frac{\alpha+\sqrt{\beta}}{2}\right)
Comparing both sides and using the inverse sine definition, infer that:
\(\alpha + \beta = 4.4\). With the condition x \in (0, π/2), verify:
x fits the range when \(\alpha + \beta \approx 4.4\).
Conclude that:
The value of \(\alpha + \beta = 4.4\), which fits the specified range correctly.
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