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IfA+B+C=180^@then prove that sin( A/2)+s...

If`A+B+C=180^@`then prove that `sin( A/2)+sin( B/2)+sin( C/2) = `
` 1+4 sin( (pi-A)/4)sin((pi-B)/4)sin ((pi-C)/4)`

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PATHFINDER-TRIGONOMETRIC RATIOS AND IDENTITIES-QUESTION BANK
  1. Find cos(alpha+beta) if tan(alpha/2) and tan (beta/2) are roots of the...

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  2. If sec alpha and cosec alpha are the roots of x^2-px+q=0 then prove...

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  3. IfA+B+C=180^@then prove that sin( A/2)+sin( B/2)+sin( C/2) = 1+4 sin...

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  4. If x+y+z=xyz then prove that (3x-x^3)/(1-3x^2)+(3y-y^3)/(1-3y^2)+(3z-z...

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  5. Simplify the product cos A cos 2A cos2^2A……cos2^(n-1)A

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  6. Prove that the value of underset(r=0)overset10sum cos^3((rpi)/3) is eq...

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  7. If sinx+cosx=m and secx+cosecx=n prove that n(m^2-1)=2m

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  8. if xsin^3theta+ycos^3theta =sin theta cos theta and x sin theta -y cos...

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  9. Show that (sin^2 theta)/(1-cot theta)+(cos^2 theta)/(1-tan theta )=1+s...

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  10. If a sec alpha +btan alpha=d and bsec alpha +a tan alpha=c prove that ...

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  11. If a cos^3theta +3a cos theta sin^2theta =x and asin^3theta+3a cos^2th...

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

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  13. If cos 2x + 2 cosx = 1 then evaluate sin^2x(2-cos^2x)

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  14. Prove that sqrt3cosec 20^@-sec20^@=4

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  15. Without using tables prove that (sin12^@)(sin 48^@)(sin 54^@)=1/8

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

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  17. Find the value of (1+cos (pi/8))(1+cos(3pi/8))(1+cos(5pi/8))(1+cos(7pi...

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  18. Find the value of (sqrt((1+sin 2A))+sqrt(1-sin 2A))/(sqrt(1+sin 2A)-sq...

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  19. Find the maximum and minimum value of 6sinx cosx +4cos2x

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  20. If f(x)=(sin3x)/sin x,X ne n pi then find range of f(x)

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