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If tan A=1/5, tanB=2/3show that cos2A=si...

If `tan A=1/5, tanB=2/3`show that `cos2A=sin2B`

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MBD PUBLICATION-TRIGONOMETRIC FUNCTIONS-QUESTION BANK
  1. If tantheta=(asinx+bsiny)/(acosx+bcosy) then show that a sin(theta-x)+...

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  2. If A+C=B show that tanA.tanB.tanC=tanB-tanA-tanC

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  3. If tan A=1/5, tanB=2/3show that cos2A=sin2B

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  4. If cos2A=tan^2B then show that cos 2B=tan^2A

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  5. In triangle ABC, prove that tan(B+C)/2=cot(A/2)

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  6. In triangle ABC , prove that cos(A+B)+sinC=sin(A+B)-cosC

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  7. If A+B+C=pi and cosA=cosB.cosC show that tanB+tanC=tanA

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  8. If A+B+C=pi and cosA=cosB.cosC show that 2cotB.cotC=1

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  9. Prove the following : cos(A-D)sin(B-C)+cos(B-D)sin(C-A)+cos(C-D)sin(A-...

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  10. Prove the following : sin2A+sin2B+sin2(A-B) = 4sinA.cosB.cos(A-B)

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  11. Prove the following : cos2A+cos2B+cos2(A-B)+1 = 4cosA.cosB.cos(A-B)

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  12. Prove the following : sin2A+sin2B+sin2C-sin2(A+B+C) 4sin(B+C)sin(C+A...

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  13. Prove the following : sinA+sin3A+sin5A =sin3A(1+2cos2A)

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  14. Prove the following : sinA-sin3A+sin5A = sin3A(2cos2A-1)

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  15. Prove the following : cos(A+B)+sin(A-B) 2sin(45^@+A)cos(45^@+B)

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  16. Prove the following : cos4A-cos4B = 8(cosA-cosB)(cosA+cosB)(cosA-sin...

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  17. Prove the following : (1-tan^2(45^@-A))/(1+tan^2(45^@-A)) = sin2A

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  18. Prove the following : (cosA+sinA)/(cosA-sinA)-(cosA-sinA)/(cosA+sinA) ...

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  19. Prove the following : (1-cos2A+sin2A)/(1+cos2A+sin2A) = tanA

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  20. Prove the following : (sin(A+B)+cos(A-B))/(sin(A-B)+cos(A+B)) = sec2...

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