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

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

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`5cos2theta+2cos^2(theta/2)+1=0`
`5(2cos^2theta-1)+(1+costheta+1=0`
`10cos^2theta-5+1+costheta+1=0`
`10cos^2theta+costheta-3=0`
`10cos^2theta+6costheta-5costheta-3=0`
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CENGAGE-TRIGONOMETRIC FUNCTIONS-Solved Examples And Exercises
  1. Prove that sum(r=1)^n(1/(costheta+"cos"(2r+1)theta))=(sinntheta)/(2si...

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

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

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

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  5. If A lies in second quadrant and 3tanA+4=0, then the value of 2cotA-5...

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  6. Solve sin2theta+costheta=0

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

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  8. Given x, y in R , x^(2) + y^(2) gt 0 . Then the range of (x^(2) + ...

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

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

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

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

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  13. If b >1,sint >0,cost >0a n d(log)b(sint)=x ,t h e n(log)b(cost) is equ...

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

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

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

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  17. The value of expression of (alphatangamma+betacotgamma)(alphacotgamma+...

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  18. Find the general solution of : sqrt(3)sec2theta=2

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  19. Find the value of 2cos^3(pi/7)-cos^2(pi/7)-cos(pi/7)

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  20. In acute angled triangle A B C ,A D is the altitude. Circle drawn with...

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