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If cosec^(2)theta+cot^(2)theta=7 find si...

If `cosec^(2)theta+cot^(2)theta=7` find `sintheta&costheta`

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To solve the equation \( \csc^2 \theta + \cot^2 \theta = 7 \) and find \( \sin \theta \) and \( \cos \theta \), we can follow these steps: ### Step 1: Use the identity for \( \csc^2 \theta \) and \( \cot^2 \theta \) We know the identity: \[ \csc^2 \theta - \cot^2 \theta = 1 \] ### Step 2: Set up the equations From the given equation: \[ \csc^2 \theta + \cot^2 \theta = 7 \quad \text{(1)} \] And from the identity: \[ \csc^2 \theta - \cot^2 \theta = 1 \quad \text{(2)} \] ### Step 3: Add equations (1) and (2) Adding both equations: \[ (\csc^2 \theta + \cot^2 \theta) + (\csc^2 \theta - \cot^2 \theta) = 7 + 1 \] This simplifies to: \[ 2 \csc^2 \theta = 8 \] ### Step 4: Solve for \( \csc^2 \theta \) Dividing both sides by 2: \[ \csc^2 \theta = 4 \] ### Step 5: Find \( \sin^2 \theta \) Since \( \csc \theta = \frac{1}{\sin \theta} \), we have: \[ \csc^2 \theta = \frac{1}{\sin^2 \theta} \] Thus, \[ \frac{1}{\sin^2 \theta} = 4 \] Taking the reciprocal gives: \[ \sin^2 \theta = \frac{1}{4} \] ### Step 6: Find \( \sin \theta \) Taking the square root: \[ \sin \theta = \frac{1}{2} \quad \text{(considering the principal value)} \] ### Step 7: Find \( \cos^2 \theta \) Using the Pythagorean identity: \[ \sin^2 \theta + \cos^2 \theta = 1 \] Substituting \( \sin^2 \theta \): \[ \frac{1}{4} + \cos^2 \theta = 1 \] Thus, \[ \cos^2 \theta = 1 - \frac{1}{4} = \frac{3}{4} \] ### Step 8: Find \( \cos \theta \) Taking the square root: \[ \cos \theta = \frac{\sqrt{3}}{2} \quad \text{(considering the principal value)} \] ### Final Answer Thus, we have: \[ \sin \theta = \frac{1}{2} \quad \text{and} \quad \cos \theta = \frac{\sqrt{3}}{2} \] ---
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ADVANCED MATHS BY ABHINAY MATHS ENGLISH-TRIGONOMETRY -EXERCISES (Multiple Choice Questions)
  1. If cosec^(2)theta+cot^(2)theta=7 find sintheta&costheta

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  2. Find the value of (sin43^(@))/(cos47^(@)).

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  3. If sintheta+cosectheta=2, then find the value of sin^(5)theta+cosec^(5...

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  4. If tantheta+cottheta=2 then find the value of tan^(2)theta+cot^(2)thet...

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  5. If sintheta+cosectheta=2, the value of sin^(100)theta+cosec^(100)the...

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  6. If (sin theta + cos theta)/(sin theta - cos theta) = (5)/(4) , the val...

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  7. (tantheta)/(1-cottheta)+(cottheta)/(1-tantheta) is equal to -

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  8. If tantheta+cottheta=2, then the value of tan^(n)theta+cot^(n)theta (0...

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  9. If (sectheta+tantheta)/(sectheta-tantheta)=(5)/(3), then sintheta is e...

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  10. If cos^(4)theta-sin^(4)theta=(2)/(3), then the value of 1-2sin^(2)thet...

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  11. tan46^(@)-cot44^(@)=?

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  12. cos51^(@)-sin39^(@)+sin37^(@)-cos53^(@)=?

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  13. If x+(1)/(x)=2costheta, then find the valueof x^(3)+(1)/(x^(3)).

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  14. If sectheta+tantheta=3, then find the value of sectheta.

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  15. If costheta=(5)/(13), then find the value of tan^(2)theta+sec^(2)theta...

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  16. If alpha+beta=90^(@),alpha=2beta, then find the value of cos^(2)alpha+...

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  17. Find the value of (1-tan^(2)22(1^(@))/(2))/(1+tan^(2)22(1^(@))/(2)).

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  18. sin^(2)88^(@)+cos^(2)88^(@)=?

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  19. If tantheta=(1)/(2)andtanphi=(1)/(3), then theta+phi=?

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  20. Find the value of (tanA+secA-1)cosA.

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  21. If 2costheta=x+(1)/(x), then find the value of 2cos^(2)theta.

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