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Prove that cos^2( pi/8)+cos^2((3pi)/8)+c...

Prove that `cos^2( pi/8)+cos^2((3pi)/8)+cos^2 ((5pi)/8)+cos^2 ((7pi)/8)=2.`

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PATHFINDER-MEASUREMENT OF ANGLES & TRIGONOMETRIC FUNCTIONS -QUESTION BANK
  1. Prove that cot^2 60^@+sin^2 45^@ +sin^2 30^@+cos^2 90^@=(13)/(12)

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  2. Solve for x :sintheta=x+1/x,x inR.

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  3. Prove that ((sin0^@+cos30^@)(sin30^@+tan45^@))/((tan30^@+cot60^@)(sec6...

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  4. Prove that cos^2( pi/8)+cos^2((3pi)/8)+cos^2 ((5pi)/8)+cos^2 ((7pi)/8)...

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  5. Evaluate cos^2((pi)/(3))+sin^2((pi)/6)-tan^2((pi)/4)

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  6. Find the degree measure of the angle subtended at the centre of a circ...

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  7. Prove that cos510^@cos330^@+sin390^@cos120^@=-1

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  8. Evaluate cosec(-1200^@).

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  9. In a DeltaABC.Prove that cos (A+B)+cosC=0.

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  10. Find x if cosec(90^@+theta)+xcostheta cot(90^@+theta)=sin(90+theta)

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  11. Prove that (1/(sec^2theta-cos^2theta)+1/(cosec^2-sin^2theta))sin^2thet...

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  12. If (cosecalpha-cotalpha)(cosecbeta-cotbeta)(cosecgamma-cotgamma)= (co...

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  13. If (ax)/costheta+(by)/(sintheta)=a^2-b^2 and (axsintheta)/(cos^2theta)...

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  14. If costheta+sintheta=sqrt2costheta, Prove that costheta-sintheta=sqrt2...

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  15. If Tn=sin^ntheta+cos^nthetaProve that (T3-T5)/(T1)=(T5-T7)/(T3)

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  16. The angular diameter of the moon 30' . How far from the eye a coin of ...

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  17. If tan^2theta=1-e^2,Prove that sectheta+tan^3thetacosectheta=(2-e^2)^(...

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  18. Prove that costheta(tantheta+2)(2tantheta+1)=2sectheta+5sintheta

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  19. Prove that sqrt((1-sintheta)/(1+sintheta))+sqrt((1+sintheta)/(1-sinthe...

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  20. If tantheta=a/b, show that (asintheta-bcostheta)/(asintheta+bcostheta)...

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