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cos120^(@)=cos(90^(@)+30^(@)) =-sin30^...

`cos120^(@)=cos(90^(@)+30^(@))`
`=-sin30^(@)=-(1)/(2)`

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sin60^(@).cos30^(@)+cos30^(@)*sin60^(@)

(cos 60^(@) xx cos 30^(@)+sin 60^(@)xx sin 30^(@))/(2 sin 30^(@) xx cos 0^(@)+ sin 90^(@))=?

Show that (i) cos60^(@)*cos30^(@)-sin60^(@)*sin30^(@)=cos90^(@) (ii) cos60^(@)=1-2sin^(2)30^(@)=2cos^(2)30^(@)-1 (iii) (tan60^(@)-tan30^(@))/(1+tan60^(@)*tan30^(@))=tan30^(@)

Verify each of the following : (i) sin60^(@)cos30^(@)-cos60^(@)sin30^(@)=sin30^(@) (ii) cos60^(@)cos30^(@)+sin60^(@)sin30^(@)=cos30^(@) (iii) 2sin 30^(@)cos30^(@)=sin60^(@) (iv) 2sin45^(@)cos45^(@)=sin90^(@)

Evaluate : cos60^(@)cos30^(@)+ sin 60^(@)sin30^(@)

The value of (1)/(2) sin ^(2) 90^(@) sin^(2) 30^(@) cos ^(2) 45^(@) + 4 tan ^(2) 30^(@) + (1)/(2) sin^(2) 90^(@) - 2 cos ^(2) 90^(@) is :

If it right to say cos(60^(@)+30^(@))=cos60^(@)cos30^(@)-sin60^(@)sin30^(@)

What is the value of (sin30^(@)+cos30^(@))/(cos30^(@)-sin30^(@)) ?

Given that sin30^(@)=1//2 and cos 30^(@)=sqrt3//2 . Determine the values of sin 60^(@), sin 120^(@), sin 240^(@), sin 300^(@) , and sin (-30^(@)) .

If cos 2x = cos 60^(@) cos 30^(@) + sin 60^(@) sin 30^(@), then the value of x is

ADVANCED MATHS BY ABHINAY MATHS ENGLISH-TRIGONOMETRY -EXERCISES (Multiple Choice Questions)
  1. cos120^(@)=cos(90^(@)+30^(@)) =-sin30^(@)=-(1)/(2)

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  2. Find the value of (sin43^(@))/(cos47^(@)).

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  3. If sintheta+cosectheta=2, then find the value of sin^(5)theta+cosec^(5...

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  4. If tantheta+cottheta=2 then find the value of tan^(2)theta+cot^(2)thet...

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  5. If sintheta+cosectheta=2, the value of sin^(100)theta+cosec^(100)the...

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  6. If (sin theta + cos theta)/(sin theta - cos theta) = (5)/(4) , the val...

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  7. (tantheta)/(1-cottheta)+(cottheta)/(1-tantheta) is equal to -

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  8. If tantheta+cottheta=2, then the value of tan^(n)theta+cot^(n)theta (0...

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  9. If (sectheta+tantheta)/(sectheta-tantheta)=(5)/(3), then sintheta is e...

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  10. If cos^(4)theta-sin^(4)theta=(2)/(3), then the value of 1-2sin^(2)thet...

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  11. tan46^(@)-cot44^(@)=?

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  12. cos51^(@)-sin39^(@)+sin37^(@)-cos53^(@)=?

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  13. If x+(1)/(x)=2costheta, then find the valueof x^(3)+(1)/(x^(3)).

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  14. If sectheta+tantheta=3, then find the value of sectheta.

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  15. If costheta=(5)/(13), then find the value of tan^(2)theta+sec^(2)theta...

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  16. If alpha+beta=90^(@),alpha=2beta, then find the value of cos^(2)alpha+...

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  17. Find the value of (1-tan^(2)22(1^(@))/(2))/(1+tan^(2)22(1^(@))/(2)).

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  18. sin^(2)88^(@)+cos^(2)88^(@)=?

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  19. If tantheta=(1)/(2)andtanphi=(1)/(3), then theta+phi=?

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  20. Find the value of (tanA+secA-1)cosA.

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  21. If 2costheta=x+(1)/(x), then find the value of 2cos^(2)theta.

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