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Let fn(theta)=(cos(theta/2)+cos2theta+co...

Let `f_n(theta)=(cos(theta/2)+cos2theta+cos((7theta)/2)+....+cos(3n-2)(theta/2))/(sin(theta/2)+sin2theta+sin((7theta)/2)+....+sin(3n-2)(theta/2))` then (a)`f_3((3pi)/(16))=sqrt(2)-1` (b) `f_5(pi/(28))=sqrt(2)+1` (c)`f_7(pi/(60))=(2+sqrt(3))` (d) none of these

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CENGAGE ENGLISH-TRIGONOMETRIC FUNCTIONS-All Questions
  1. P(9,2) = P(x,2).Find x.

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  2. If |2sintheta-cos e ctheta|geq1 and theta!=(npi)/2,n in Z , then cos2...

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  3. Let fn(theta)=(cos(theta/2)+cos2theta+cos((7theta)/2)+....+cos(3n-2)(t...

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  4. Each side of triangle ABC is divided into three equal parts. Find the ...

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  5. Which of the following is not the solution of the equation sin5x=16sin...

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  6. (1+tanalphatanbeta)^2+(tanalpha-tanbeta)^2=

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  7. If cot^3alpha+cot^2alpha+cotalpha=1 then (a) cos2alpha.tanalpha=-1 ...

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  8. Find the rang of f(x)=sqrt(sin^2x-6sinx+9)+3

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  9. The number of solution of the equation |2sinx-sqrt(3)|^2cos^(2x-3cosx+...

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  10. In triangle A B C ,l e tR=c i r c u m r a d i u s ,r= i n r a d i u ...

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  11. The expression cos^2(alpha+beta)+cos^2(alpha-beta)-cos2alpha.cos2beta,...

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  12. In triangle ABC, if A - B = 120 and R = 8r, where R and r have their u...

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  13. The sum of all the solution in [0,4pi] of the equation tanx+cotx+1=co...

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  14. If f(x , y) satisfies the equation 1+4x-x^2=sqrt(9sec^2y+4cos e c^2y) ...

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

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  16. A B C is an equilateral triangle of side 4c mdot If R , r, a n d,h are...

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  17. The total number of solutions of loge |sin x| = -x^2 +2x in [0,pi] is...

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  18. If sin^2theta1+sin^2theta2+sin^2theta3=0, then which of the following ...

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  19. The length of the shadow of a vertical pole of height h , thrown by th...

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  20. For real values of 'x' , Which of the following is/are always positiv...

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