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(i) If sin the sec theta sec theta =-1 a...

(i) If sin the `sec theta sec theta` =-1 and theta lies in the second quadrant find `"sin" theta` and `sec theta`
(ii) If `cos theta cosec theta` =- 1 and theta lies in the in the fourth quadrient find `cos theta and cosectheta`

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Let's solve the two parts of the question step by step. ### Part (i) **Given:** \[ \sin \theta \sec \theta = -1 \] **Condition:** \(\theta\) lies in the second quadrant. **Step 1:** Rewrite the equation using the identity for secant. \[ \sec \theta = \frac{1}{\cos \theta} \] Thus, the equation becomes: \[ \sin \theta \cdot \frac{1}{\cos \theta} = -1 \] This simplifies to: \[ \frac{\sin \theta}{\cos \theta} = -1 \] **Hint:** Remember that \(\tan \theta = \frac{\sin \theta}{\cos \theta}\). **Step 2:** Recognize that \(\tan \theta = -1\). Since \(\theta\) is in the second quadrant, where tangent is negative, we can conclude: \[ \tan \theta = -1 \implies \theta = 135^\circ \quad (\text{or } 90^\circ + 45^\circ) \] **Step 3:** Find \(\sin \theta\) and \(\sec \theta\). Using the angle \(135^\circ\): \[ \sin 135^\circ = \sin(90^\circ + 45^\circ) = \sin 45^\circ = \frac{1}{\sqrt{2}} \] \[ \sec 135^\circ = \frac{1}{\cos 135^\circ} = \frac{1}{-\cos 45^\circ} = -\sqrt{2} \] **Final Values:** \[ \sin \theta = \frac{1}{\sqrt{2}}, \quad \sec \theta = -\sqrt{2} \] ### Part (ii) **Given:** \[ \cos \theta \csc \theta = -1 \] **Condition:** \(\theta\) lies in the fourth quadrant. **Step 1:** Rewrite the equation using the identity for cosecant. \[ \csc \theta = \frac{1}{\sin \theta} \] Thus, the equation becomes: \[ \cos \theta \cdot \frac{1}{\sin \theta} = -1 \] This simplifies to: \[ \frac{\cos \theta}{\sin \theta} = -1 \] **Hint:** Remember that \(\cot \theta = \frac{\cos \theta}{\sin \theta}\). **Step 2:** Recognize that \(\cot \theta = -1\). Since \(\theta\) is in the fourth quadrant, where cotangent is negative, we can conclude: \[ \cot \theta = -1 \implies \theta = 315^\circ \quad (\text{or } 360^\circ - 45^\circ) \] **Step 3:** Find \(\cos \theta\) and \(\csc \theta\). Using the angle \(315^\circ\): \[ \cos 315^\circ = \cos(360^\circ - 45^\circ) = \cos 45^\circ = \frac{1}{\sqrt{2}} \] \[ \sin 315^\circ = \sin(360^\circ - 45^\circ) = -\sin 45^\circ = -\frac{1}{\sqrt{2}} \] Thus, \[ \csc 315^\circ = \frac{1}{\sin 315^\circ} = \frac{1}{-\frac{1}{\sqrt{2}}} = -\sqrt{2} \] **Final Values:** \[ \cos \theta = \frac{1}{\sqrt{2}}, \quad \csc \theta = -\sqrt{2} \] ### Summary of Answers: 1. For part (i): \(\sin \theta = \frac{1}{\sqrt{2}}, \sec \theta = -\sqrt{2}\) 2. For part (ii): \(\cos \theta = \frac{1}{\sqrt{2}}, \csc \theta = -\sqrt{2}\)
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