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If cosectheta-cottheta =2, find the valu...

If `cosectheta-cottheta =2`, find the value of `cosec^(2)theta+cot^(2)theta`.

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To solve the problem, we need to find the value of \( \csc^2 \theta + \cot^2 \theta \) given that \( \csc \theta - \cot \theta = 2 \). ### Step-by-Step Solution: 1. **Start with the given equation:** \[ \csc \theta - \cot \theta = 2 \] 2. **Rationalize the expression:** Multiply both sides by \( \csc \theta + \cot \theta \): \[ (\csc \theta - \cot \theta)(\csc \theta + \cot \theta) = 2(\csc \theta + \cot \theta) \] 3. **Use the difference of squares:** The left-hand side can be simplified using the identity \( a^2 - b^2 \): \[ \csc^2 \theta - \cot^2 \theta = 2(\csc \theta + \cot \theta) \] 4. **Substitute the identity for \( \csc^2 \theta \):** Recall that \( \csc^2 \theta = 1 + \cot^2 \theta \): \[ (1 + \cot^2 \theta) - \cot^2 \theta = 2(\csc \theta + \cot \theta) \] This simplifies to: \[ 1 = 2(\csc \theta + \cot \theta) \] 5. **Solve for \( \csc \theta + \cot \theta \):** Rearranging gives: \[ \csc \theta + \cot \theta = \frac{1}{2} \] 6. **Now we have two equations:** - \( \csc \theta - \cot \theta = 2 \) (Equation 1) - \( \csc \theta + \cot \theta = \frac{1}{2} \) (Equation 2) 7. **Add the two equations:** \[ (\csc \theta - \cot \theta) + (\csc \theta + \cot \theta) = 2 + \frac{1}{2} \] This simplifies to: \[ 2 \csc \theta = \frac{5}{2} \] 8. **Solve for \( \csc \theta \):** \[ \csc \theta = \frac{5}{4} \] 9. **Find \( \cot \theta \):** Use the identity \( \cot^2 \theta = \csc^2 \theta - 1 \): \[ \cot^2 \theta = \left(\frac{5}{4}\right)^2 - 1 = \frac{25}{16} - 1 = \frac{25}{16} - \frac{16}{16} = \frac{9}{16} \] 10. **Now calculate \( \csc^2 \theta + \cot^2 \theta \):** \[ \csc^2 \theta + \cot^2 \theta = \left(\frac{5}{4}\right)^2 + \frac{9}{16} = \frac{25}{16} + \frac{9}{16} = \frac{34}{16} = \frac{17}{8} \] ### Final Answer: \[ \csc^2 \theta + \cot^2 \theta = \frac{17}{8} \]
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