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If the sides be a,b,c then show that a `cos A + B + cos B+ cos C = 4R sin A sin B sin C`

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MODERN PUBLICATION-TRIGNOMETRY-EXERCISE
  1. In any triangle ABC, prove that : (b-c)/a= (sin frac (B-C)(2))/(cos fr...

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

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  3. If the sides be a,b,c then show that a cos A + B + cos B+ cos C = 4R s...

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  4. In any triangle ABC, prove that : a sin (B -C) + b sin (C -A) +c sin (...

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  5. In any triangle A B C , prove that: (a^2sin(B-C))/(sinB+sin C)+(b^2sin...

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  6. In any triangle A B C , prove that: (a^2sin(B-C))/(sinB+sin C)+(b^2sin...

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  7. In any triangle ABC, prove that : (a^2-b^2)/(cos A+cos B)+(b^2-c^2)/(c...

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  8. In any triangle ABC, prove that : a^3 sin (B-C)+ b^3 sin (C-A)+ c^3 s...

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  9. In any triangle ABC, prove that : a (cos B + cos C) = 2 (b +c) sin^2 ...

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  10. In any triangle ABC, prove that : a (cos C - cos B) = 2 (b-c) cos^2 fr...

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  11. In any triangle ABC, prove that : (a sin(B-C))/(b^2-c^2)= (b sin (C-A)...

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  12. In any triangle ABC, prove that : (c^2-a^2+b^2) tan A= (a^2-b^2+ c^2) ...

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  13. In any DeltaABC, 2 [bc cos A + ca cos B+ ab cos C]=

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  14. In any triangle ABC, prove that : (b + c) cos A + (c + a) cos B + (a +...

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  15. In any triangle ABC, prove that : (b^2-c^2) cot A + (c^2-a^2)cot B +(...

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  16. In any triangle ABC, prove that : (b^2-c^2) tan B tan C + (c^2-a^2)tan...

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  17. In any triangle ABC, prove that : ((b^2-c^2))/a^2 sin 2A+ ((c^2-a^2))/...

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  18. In any triangle ABC, prove that : (tanC)/(tanA)= (b^2+c^2-a^2)/(a^2+b^...

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  19. In any triangle ABC, prove that : b^2 sin 2C + c^2 sin 2B = 2 bc sin A...

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  20. In any triangle ABC : If a cos A = b cos B, prove that either the tri...

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