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If cos alpha =1/2(x+1/x),cos beta=1/2(y+...

If `cos alpha =1/2(x+1/x),cos beta=1/2(y+1/y)` then evaluate `cos(alpha-beta)`

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`cos(alpha-beta)=1/2(x/y+y/x)`
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PATHFINDER-TRIGONOMETRIC RATIOS AND IDENTITIES-QUESTION BANK
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  6. Without using tables prove that (sin12^@)(sin 48^@)(sin 54^@)=1/8

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  7. In any triangle prove that cot(A/2)+cot (B/2)+cot(C/2)=cot(A/2)cot(B/2...

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  15. Show that sin(pi/n)+sin (3pi/n)+sin (5pi/n)+….n terms=0

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  16. .(tantheta +sectheta-1)/(tantheta -sectheta+1)=

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  18. (cosec(2pi+theta)cos(2pi+theta)tan(pi/2+theta))/(sec(pi/2+theta)costhe...

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  19. In triangle ABC, right angled at C, (tanA+tanB) equal to

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  20. If sintheta and costheta are the roots of the equation ax^2-bx+c=0, th...

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