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If A= 45^@, verify that : cos 2A = cos^...

If `A= 45^@`, verify that : `cos 2A = cos^2 A - sin^2 A.`

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If A= 30^@ verify that :- cos2A= 2 cos^2 A-1 .

If A= 30^@ verify that :- cos2A= cos^2A-sin^2A .

If A= 45^@ , verify that : sin 2A =2 sin A cos A .

If A= 30^@ verify that :- cos2A=1- 2sin^2A .

If A= 30^@ verify that :- cos2A= (1-tan^2A)/(1+tan^2A) .

If A= 30^@ verify that :- tanA= sqrt((1-cos^2A)/cos^2A .

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

If A= 30^@ and B= 60^@ , verify that : sin (A + B) = sin A cos B + cos A sin B .

If A + B + C =180^@ , prove that : cos^2 A- cos^2 B-cos^2 C=2 cos A sin B sinC -1 .

If A + B + C =pi , prove that : cos 2A - cos 2B + cos 2C= 1-4 sin A cos B sin C .

MODERN PUBLICATION-TRIGNOMETRY-EXERCISE
  1. Prove that : cot^2 30^@, cot^2 45^@, cot^2 60^@ are in G.P.

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  2. If A= 45^@, verify that : sin 2A =2 sin A cos A .

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  3. If A= 45^@, verify that : cos 2A = cos^2 A - sin^2 A.

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  4. If theta = 30^@, verify that tan 2 theta= (2 tan theta)/(1- tan^2 thet...

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  5. If A= 30^@ and B= 60^@, verify that : sin (A + B) = sin A cos B + co...

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  6. Given tan 2A = (2 tan A)/(1-tan^2A). If tan 30^@= 1/sqrt3, verify that...

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  7. Find the value of theta (0^@ le theta le 90^@) satisfying : tan theta+...

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  8. Find the value of theta (0^@ le theta le 90^@) satisfying : 2 sin^2 th...

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  9. Find the value of theta (0^@ le theta le 90^@) satisfying : 2 cos^2 th...

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  10. If sin theta= 21/29, prove that sec theta+ tan theta= 2 1/2 if theta l...

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  11. What will be the value of the expression sec theta+ tan theta and sin ...

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  12. What will be the value of the expression sec theta+ tan theta and sin ...

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  13. If sin(B +C-A)= cos(C+A-B) =tan (A+B-C)=1, find A, B, C which are posi...

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  14. Find the value of : cos 210^@.

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  15. Find the value of : sin 225^@.

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  16. Find the value of : sin 765^@.

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  17. Find the value of : tan 330^@.

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  18. Find the value of : tan frac (19 pi)(3).

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  19. Find the value of : cot (-315^@).

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  20. Find the value of : cot ((-15 pi)/4) .

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