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If A + B + C =180^@, prove that : cot fr...

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)`.

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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) .

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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 cos frac (A)(2)cos frac (B)(2)sin frac (C)(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) .

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MODERN PUBLICATION-TRIGNOMETRY-EXERCISE
  1. If A + B + C =180^@, prove that : cot frac (A)(2)+cot frac (B)(2)+cot ...

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  2. Find the radian measure corresponding to the following degree measure ...

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  3. Find the radian measure corresponding to the following degree measure ...

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  4. Find the radian measure corresponding to the following degree measure ...

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  5. Find the radian measures corresponding to the following degree measure...

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  6. Find the radian measure corresponding to the following grade measure :...

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  7. Find the radian measure corresponding to the following grade measure :...

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  8. Find the radian measure corresponding to the following grade measure :...

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  9. Find thedegree measure corresponding to the following measure. (Use pi...

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  10. Find thedegree measure corresponding to the following measure. (Use pi...

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  11. Find thedegree measure corresponding to the following measure. (Use pi...

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  12. Find thedegree measure corresponding to the following measure. (Use pi...

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  13. The angles of a triangle are3x^@, ((4x)/3)^g and (2 pi x)/75 radians. ...

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  14. Express the radians the fourth angle of a quadrilateral which has thre...

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  15. The sum of two angles is 80 grades and their difference is 18^@. Find ...

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  16. The angles of a triangle are in the ratio 1 : 2: 3. Find the angles in...

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  17. The vertical angle of an isosceles triangle is 2/3 rd of each of its b...

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  18. In a right-angled triangle, the difference between two acute angles is...

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  19. The wheel of a carriage is 91 cm in diameter and makes 5 revolutions p...

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  20. A wheel makes 360 revolutions in one minute. Through how many radians ...

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  21. Find the length of the arc of a circle of radius 5 cm subtending an an...

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