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Prove that cos6^@ . cos42^@. cos66^@ cos...

Prove that `cos6^@ . cos42^@. cos66^@ cos78^@= 1/16`

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Prove that 4 cos 6^(@) cos 42 ^(@) cos 66^(@) cos 78^(@) = (1)/(4).

Prove that cos 36^(@) cos 72^(@) cos 108^(@) cos 144^(@)=1//16 .

Prove that cos20^0cos40^0cos60^0cos80^0=1/(16)dot

Prove that cos36^0cos72^0cos108^0cos144^0=1/(16)dot

Prove that : cos 20^0cos 40^0cos 60^0cos 80^0=1/(16)

Prove that: sin6^(@)sin42^(@)sin66^(@)sin78^(@)=1/16

Prove that: cos20^0cos40^0cos60^0cos80^0=1/(16)

Prove that cos 20^(@) cos 40^(@) cos 80^(@) = (1)/(8).

Prove that: cos 78^0cos 42^0cos 36^0=1/8

Prove that: cos 78^0cos 42^0cos 36^0=1/8

RD SHARMA ENGLISH-TRIGONOMETRIC RATIOS OF MULTIPLE AND SUBMULTIPLE ANGLES-All Questions
  1. Prove that: cos 78^0cos 42^0cos 36^0=1/8

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  2. Show that cos(pi/15)cos((2pi)/15)cos((3pi)/15)cos((4pi)/15)cos((5pi)/1...

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  3. Prove that cos6^@ . cos42^@. cos66^@ cos78^@= 1/16

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  4. Prove that: sin6^0sin42^0sin 66^0sin 78^0=1/(16)

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  5. Prove that: sin36^0s in 72^0s in 108^0s in 144^0=5/(16)dot

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  6. If cos4x=1+ksin^2x cos^2x , then write the value of kdot

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  7. If tanx/2=m/n ,\ then write the the value of msinx+n\ cos xdot

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  8. If pi/2 < theta < (3pi)/2 then write the value of sqrt((1+cos2theta)...

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  9. If pi/2<theta<pi,then write the value of sqrt(2+sqrt(2+2cos2theta)) in...

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  10. If pi/2<theta<pi , then write the value of sqrt((1-cos2theta)/(1+cos2t...

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  11. If pi<theta<(3pi)/2 , then write the value of sqrt((1-cos2theta)/(1+co...

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  12. Write the value of cos^2 76^@+cos^2 16^@- cos76^@ cos16^@

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  13. If (pi/4)< theta <(pi/2),then write the value of sqrt(1-sin2theta)

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  14. Prove that: cos(pi/7)cos(2pi/7)cos(4pi/7)=-1/8,

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  15. If sin x+cos x=a , find the value of sin^6x+cos^6xdot

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  16. If sin x+cos x=a , find the maximum and minimum value of a

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  17. 8*sin(x/8)*cos(x/2)*cos(x/4)*cos(x/8)=

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  18. Show that cos(pi/65)cos((2pi)/65)cos((4pi)/65)cos((8pi)/65)cos((16pi)/...

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  19. For all real values of x ,cotx-2cot2x is equal to a.tan2x b. t a n x c...

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  20. The value of 2tanpi/(10)+3secpi/(10)-\ 4cospi/(10) is 0 b. 1 c. sqrt(5...

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