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If A + B + C =180^@, prove that : sin^2 ...

If `A + B + C =180^@`, prove that : `sin^2 frac (A)(2)+ sin^2 frac (B)(2)-sin^2 frac (C)(2)=1-2 cos frac (A)(2)cos frac (B)(2)sin frac (C)(2)`.

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If A + B + C =180^@ , prove that : sin^2 frac (A)(2)+ sin^2 frac (B)(2)+sin^2 frac (C)(2)=1-2 sin frac (A)(2)sin frac (B)(2)sin frac (C)(2) .

If A + B + C =180^@ , prove that : cos^2 frac (A)(2)+ cos^2 frac (B)(2)+cos^2 frac (C)(2)=2+2 sin frac (A)(2)sin frac (B)(2)sin frac (C)(2) .

If A + B + C =pi , prove that : cos^2 frac (A)(2)+cos^2 frac (B)(2)-cos^2 frac (C)(2)= 2 cos frac (A)(2) cos frac (B)(2) sin frac (C)(2) .

If A + B + C =180^@ , prove that : cot frac (A)(2)+cot frac (B)(2)+cot frac (C)(2)= cot frac (A)(2) cot frac (B)(2) cot frac (C)(2) .

In any triangle ABC, prove that : sin frac (A)(2) +sin frac (B)(2)+sin frac (C)(2)=1+4 sin frac (pi-A)(4) sin frac (pi-B)(4) sin frac (pi-C)(4) .

If A + B + C =180^@ , prove that : tan frac (A)(2) tan frac (B)(2)+ tan frac (B)(2) tan frac (C)(2) +tan frac (C)(2) tan frac (A)(2)=1 .

Prove that : sin^2 frac (pi)(6)+ cos^2 frac(pi)(3)- tan^2 frac(pi)(4)=-1/2 .

Prove that: sin^2frac (pi)(6)+cos^2frac (pi)(3)-tan^2frac (pi)(4)=-1/2

Prove that : sin^2 frac (pi)(8)+ sin^2 frac (3pi)(8)+ sin^2 frac (5pi)(8)+sin^2 frac (7pi)(8)=2 .

In any triangle ABC, prove that : cos frac (A)(2) +cos frac (B)(2)+cos frac (C)(2)= 4 cos frac (pi-A)(4) cos frac (pi-B)(4) cos frac (pi-C)(4) .

MODERN PUBLICATION-TRIGNOMETRY-EXERCISE
  1. If A + B + C =180^@, prove that : cos^2 A- cos^2 B-cos^2 C=2 cos A sin...

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  2. If A + B + C =180^@, prove that : sin^2 frac (A)(2)+ sin^2 frac (B)(2)...

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  3. If A + B + C =180^@, prove that : sin^2 frac (A)(2)+ sin^2 frac (B)(2)...

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  4. If A + B + C =180^@, prove that : cos^2 frac (A)(2)+ cos^2 frac (B)(2)...

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  5. If A + B + C =pi/2, prove that : cos^2 A +cos^2 B+cos^2 C= 2+2 sin A s...

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  6. If A + B + C =pi/2, prove that : sin^2 A +sin^2 B+sin^2 C= 1-2 sin A s...

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  7. If A + B + C =360^@, prove that : 1-cos^2 A-cos^2 B-cos^2 C+2 cos A co...

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  8. If A + B + C =180^@, prove that : tan A + tan B + tan C = tan A tan B ...

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  9. If A + B + C =180^@, prove that : tan frac (A)(2) tan frac (B)(2)+ tan...

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  10. If A + B + C =180^@, prove that : tan 2A + tan 2B + tan 2C = tan 2A ta...

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  11. If A + B + C =pi/2, prove that : tan A tan B + tan B tanC +tanC tan A=...

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  12. If A + B + C =pi/2, prove that : cot A + cot B + cot C = cot A cot B c...

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  13. Find the values of the following : sin 48^@.

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  14. Find the values of the following : sin 23^@ 26'.

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  15. Find the values of the following : cos 20^@ 10’.

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  16. Find the values of the following : cos 16^@ 11’.

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  17. Find the values of the following : tan 54^@ 30’.

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  18. Find the values of the following : tan 42^@ 6’.

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  19. Find the values of the following : cot 131^@ 20’.

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  20. Find the values of the following : cot 46^@ 26’.

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