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

If `A + B + C =360^@`, prove that : `1-cos^2 A-cos^2 B-cos^2 C+2 cos A cosB cos C=0`.

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MODERN PUBLICATION-TRIGNOMETRY-EXERCISE
  1. 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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  2. 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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  3. 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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  4. If A + B + C =180^@, prove that : tan A + tan B + tan C = tan A tan B ...

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

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

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

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

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

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

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

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

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

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

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

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

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  17. Find theta, 0< theta <90^@, if : sin theta = 0.7071.

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  18. Find theta, 0< theta <90^@, if : cos theta = 0.9604.

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  19. Find theta, 0< theta <90^@, if : tan theta = 34.37.

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  20. Find theta, 0< theta <90^@, if : cot theta = 3.018.

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