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Prove that sum(r=1)^n(1/(costheta+"cos"(...

Prove that `sum_(r=1)^n(1/(costheta+"cos"(2r+1)theta))=(sinntheta)/(2sintheta* costheta*cos (n+1)theta),( "where" , n in N)dot`

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CENGAGE PUBLICATION-TRIGONOMETRIC FUNCTIONS-All Questions
  1. Suppose ABCD (in order) is a quadrilateral inscribed in a circle. Whic...

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  2. Solve sec4theta-sec2theta=2

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  3. Prove that sum(r=1)^n(1/(costheta+"cos"(2r+1)theta))=(sinntheta)/(2sin...

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  4. ABC is an isosceles triangle inscribed in a circle of radius rdot If A...

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  5. Find which of the following functions is even or odd ? f(x)=x^2+|sinx|...

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  6. Solve : 5cos2theta+2cos^2(theta/2)+1=0,-pi lt theta lt pi

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  7. If x^2+y^2=x^2y^2 then find the range of (5x+12 y+7x y)/(x y) .

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  8. In triangle A B C , if cosA+cosB+cosC=7/4, t h e n R/r is equal to 3/4...

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  9. If 3tanA+4=0, then the value of 2cotA-5cosA+sinA is equal to

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  10. Solve sin2theta+costheta=0

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  11. Two medians drawn from the acute angles of a right angled triangle int...

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  12. For all, x ,y in Rdot find the range of ((x+y)(1-x y))/((1+x^2)(1+y^2...

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  13. A circle centred at 'O' has radius 1 and contains the point A. Segment...

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  14. Solve that equation : costheta+cos3theta-2cos2theta=0

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  15. If x^2+y^2=4 then find the maximum value of (x^3+y^3)/(x+y)

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  16. If inside a big circle exactly n(nlt=3) small circles, each of radius ...

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  18. Find the general values of x and y satisfying the equations 5sinx cosy...

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  19. If (x^2)/4+(y^2)/9=1, then find the range of 2x+ydot

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  20. If A is the area and 2s is the sum of the sides of a triangle, then Al...

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