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Show thatcos((2pi)/7)+cos((4pi)/7)+cos((...

Show that`cos((2pi)/7)+cos((4pi)/7)+cos((6pi)/7)=-1/2`

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Prove that cos((2pi)/7)+cos((4pi)/7)+cos((6pi)/7)=-1/2

Show that 16cos((2pi)/(15))cos((4pi)/(15))cos((8pi)/(15))cos((16pi)/(15))=1

The value of cos((2pi)/7)cos((4pi)/7)cos((6pi)/7) is

show that cos^2(pi/9)+cos^2((2pi)/9)+cos^2((4pi)/9)=3/2

Prove that cos((2pi)/(15))cos((4pi)/(15))cos((8pi)/(15))cos((16pi)/(15))=1/(16)

Show that cos(pi/11)+cos((3pi)/11)+cos((5pi)/11)+cos((7pi)/11)+cos((9pi)/11)=1/2

Show that cos(pi/11)cos((2pi)/11)cos((3pi)/11)cos((4pi)/11)cos((5pi)/11)=1/32

The value of cos(pi/7)+cos((2pi)/7)+cos((3pi)/7)+cos((4pi)/7)+cos((5pi)/7) +cos((6pi)/7)+cos((7pi)/7) is

Prove that 4cos(2pi)/7dotcospi/7-1=2cos(2pi)/7dot

If cos(pi/7), cos((3pi)/7), cos((5pi)/7) are the roots of the equation 8x^3-4x^2-4x+1=0 The value of sec(pi/7)+sec((3pi)/7)+sec((5pi)/7) is

UNITED BOOK HOUSE-MODEL QUESTION PAPERS-SET 3-EXERCISE
  1. In.an examination. 50%of the condidates have passed in mathematics 50%...

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  2. If A,B,(A - B)are positive acute angles, then prove that geometrically...

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  3. Show thatcos((2pi)/7)+cos((4pi)/7)+cos((6pi)/7)=-1/2

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  4. Show that a^6+a^4+a^2+1=0,when a=1/sqrt2(1+i)

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  5. Prove by mathematical induction:(3^(4n+1)+2^(2n+2))is divisible by 7.

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  6. Show that the co-efficient of the middle term of the expansion of(1+x)...

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  7. If (y/z)^a.(z/x)^b.(x/y)^c=1and a,b,c are in A.P ,show that x,y,z are ...

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  8. In /\XYZthe equation of the perpendicularbisector of XY and XZ arc x-y...

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  9. Find the distance of the point (3. 5) from the line 2x + 3y = 14measur...

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  10. The end’ points of a rod having length l are moving a long with two st...

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  11. Find the equation of a circle .which passes through (-2. 1) and touche...

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  12. Evaluate:lim(x-0)((e^x-1)log5(1+5x))/(sin^2x)

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  13. Differentiate a^x with respect to x (a> 0) with the help 1st principle...

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  14. ‘I80 is the multiple of 4 or 5 examine the validity of the compound st...

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  15. ‘x is such a real number that 4x^3 + 3x= 0, then x = O’. Find the trut...

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  16. The AM and SD of the marks obtained in the subjects' Bengali, .English...

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  17. If cosalpha=siny/sinx,cosbeta=sinz/sinxand cos(alpha-beta)=siny sinz.S...

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  18. Solve :16^(sin^2x)+16^(cos^2x)=10.[0lexlepi]

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  19. Find the common solution region by. the graphical method.3x+2yle18,x+2...

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  20. Solve :x^2+x/sqrt2+1=0

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