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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 PUBLICATION-TRIGONOMETRIC FUNCTIONS-All Questions
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  2. Find which of the following functions is even or odd ? f(x)=x^2+|sinx|...

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

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  7. Solve sin2theta+costheta=0

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

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

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

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

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

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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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