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If A,B and C are interior angle of a tri...

If A,B and C are interior angle of a triangle ABC,then show that `sin(B+C)/2=cos(A/2)`

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R G PUBLICATION-INTRODUCTION TO TRIGONOMETRY-EXERCISE
  1. If tanA=cotB,prove that A+B=90^@

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  2. If sec 4A=cosec(A-20^@),where 4A is an acute angle,find the value of A...

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  3. If A,B and C are interior angle of a triangle ABC,then show that sin(B...

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  4. Express sin67^@+cos75^@in terms of trigonometric ratios of angles betw...

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  5. Express the triangle ratio sinA,secA and tanA in terms of cotA.

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  6. Write all the other trigonometric ratios of angleA in terms of sec A.

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  7. Evaluate :(i)(Sin^2 63^@+Sin^2 27^@)/(Cos^2 17^@+Cos^2 73^@)

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  8. Evaluate :(ii)Sin25^@ Cos65^@+Cos25^@Sin65^@

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  9. Choose the correct option.Justify your choice:(i)9 sec^2 A-9 tan^2 A ...

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  10. Choose the correct option.Justify your choice:(ii)(1+tan theta+sec the...

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  11. Choose the correct option.Justify your choice:(iii)(secA+tanA)(1-sinA)...

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  12. Choose the correct option.Justify your choice:(iv)(1+tan^2A)/(1+cot^2A...

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  13. Prove the following identities,where the angles involves are acute ang...

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  14. Prove the following identities,where the angles involves are acute ang...

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  15. Prove the following identities,where the angles involves are acute ang...

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  16. Prove the following identities,where the angles involves are acute ang...

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  17. Prove the following identities,where the angles involves are acute ang...

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  18. Prove the following identities,where the angles involves are acute ang...

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  19. Prove the following identities,where the angles involves are acute ang...

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  20. Prove the following identities,where the angles involves are acute ang...

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