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Statement (A) : If tantheta+cottheta=2 ,...

Statement (A) : If `tantheta+cottheta=2` , then for all `n epsilon N, tan^(n)theta+cot^(n)theta=2`
Reason (R ) : For all `n epsilon N, tan theta+cot theta=tan^(n)theta+cot^(n)theta`

A

1. Both A and R are correct and R is the correct explanation of A .

B

2. Both A and R are correct but R is not a correct explanation of A .

C

3. A is correct, R is incorrect .

D

4. A is incorrect, R is correct .

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The correct Answer is:
To solve the problem, we need to analyze the given statement (A) and reason (R) regarding the trigonometric functions. ### Step 1: Analyze Statement (A) The statement claims that if \( \tan \theta + \cot \theta = 2 \), then for all \( n \in \mathbb{N} \), \( \tan^n \theta + \cot^n \theta = 2 \). #### Explanation: - We know that \( \tan \theta + \cot \theta = 2 \) holds true when \( \theta = 45^\circ \) because: \[ \tan 45^\circ = 1 \quad \text{and} \quad \cot 45^\circ = 1 \] Thus, \( \tan 45^\circ + \cot 45^\circ = 1 + 1 = 2 \). ### Step 2: Check for \( n = 1 \) For \( n = 1 \): \[ \tan^1 \theta + \cot^1 \theta = \tan \theta + \cot \theta = 2 \] This holds true. ### Step 3: Check for \( n = 2 \) For \( n = 2 \): \[ \tan^2 \theta + \cot^2 \theta = (\tan \theta + \cot \theta)^2 - 2 \tan \theta \cot \theta \] Since \( \tan \theta \cot \theta = 1 \), we have: \[ \tan^2 \theta + \cot^2 \theta = 2^2 - 2 = 4 - 2 = 2 \] This also holds true. ### Step 4: General Case for \( n \) For any natural number \( n \): Using the identity: \[ \tan^n \theta + \cot^n \theta = (\tan \theta + \cot \theta)(\tan^{n-1} \theta + \cot^{n-1} \theta) - \tan \theta \cot \theta (\tan^{n-2} \theta + \cot^{n-2} \theta) \] This recursion shows that if \( \tan \theta + \cot \theta = 2 \), then \( \tan^n \theta + \cot^n \theta \) will also equal 2 for all \( n \in \mathbb{N} \). ### Conclusion for Statement (A) Thus, Statement (A) is correct. ### Step 5: Analyze Reason (R) The reason states that \( \tan \theta + \cot \theta = \tan^n \theta + \cot^n \theta \) for all \( n \in \mathbb{N} \). #### Explanation: - This is not true in general. The equality \( \tan \theta + \cot \theta = \tan^n \theta + \cot^n \theta \) does not hold for all angles \( \theta \) unless \( \theta = 45^\circ \). ### Conclusion for Reason (R) Thus, Reason (R) is incorrect. ### Final Conclusion - Statement (A) is true. - Reason (R) is false.
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LUCENT PUBLICATION-TRIGONOMETRIC RATIO OF SPECIFIC ANGLES-Exercise 10A
  1. In DeltaABC, /ABC=60^(@) and AD is perpendicular from A to BC . If AB=...

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  2. If 0^(@)lethetale90^(@) then for any value of theta which one is corre...

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  3. If 0^@ lt theta lt 90^@, then the value of sin theta + cos theta is

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  4. If sin theta+cosec theta=2 then value of sin^(4)theta+cos^(4)theta ?

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  5. If sec theta = (13)/( 5) , then what is the value of (2 sin theta - ...

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  6. If 0^(@)lexle90^(@) and sinx+sqrt(3)cosx=1 , then what is the value of...

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  7. In a right angled DeltaABC if /B=90^(@),AC=2sqrt(5) and AB-BC=2 then w...

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  8. Statement (A) : If tantheta+cottheta=2 , then for all n epsilon N, tan...

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  9. What is the value of expression cos^(2)((pi)/(8))+4cos^(2)((pi)/(4))-s...

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  10. If qcosectheta=p and theta is acute then value of (sqrt(p^(2)-q^(2)))t...

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  11. If 2x^(2)cos 60^(@)-4cot^(2)45^(@)-2tan 60^(@)=0, then what is the val...

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  12. If 13 cos theta=12k-5 where 0lethetale90^(@) and k is an integer then ...

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  13. Statement (A) : tan50^(@)gt1 Reason (R ) : For 0^(@)ltthetalt90^(@),...

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  14. Which one of the following is true ?

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  15. (kcosec^(2)30^(@).sec^(2)45)/(8cos^(2)45^(@).sin^(2)60^(@))=tan^(2)60^...

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  16. If sinalpha+cosbeta=2(o^(@)lebetaltalphale90^(@)) , then sin((2alpha...

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  17. Find the value of cot10^(@).cot20^(@).cot60^(@).cot70^(@).cot80^(@).

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  18. If tantheta=1, then the value of (8sintheta+5cos theta)/(sin^(3)thet...

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  19. What of the value of tan.(pi)/(8).tan.(pi)/(12).tan.(pi)/(4).tan.(3pi)...

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  20. If tan15^(@)=2-sqrt(3) then value of tan15^(@)cot75^(@)+tan75^(@)cot15...

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