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Prove that ("a c o s"A+b cosB+c cosC)/(a...

Prove that `("a c o s"A+b cosB+c cosC)/(a+b+c)=r/Rdot`

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CENGAGE PUBLICATION-TRIGONOMETRIC FUNCTIONS-All Questions
  1. If (sec^4theta)/a+(tan^4theta)/b=1/(a+b), then prove that |b|lt=|a| .

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  2. Prove that: ((cosA+cos B)/(sinA-sinB))^n+((sinA+sinB)/(cosA-cosB))^n={...

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  3. Prove that ("a c o s"A+b cosB+c cosC)/(a+b+c)=r/Rdot

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  4. Find the number of solution of the equation 1+e^(cot^2x)=sqrt(2|sinx|-...

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  5. If a^2+b^2+2a bcostheta=1,c^2+d^2+2c dcostheta=1 and a c+b d+(a d+b c)...

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  6. If r1 =r2+r3+r, prove that the triangle is right angled.

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  7. Find the number of solution of theta in [0,2pi] satisfying the equati...

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  8. Prove that (cosalpha+cosbeta)^2+(sinalpha+sinbeta)^2=4cos^2((alpha-bet...

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  9. Let A=sinx+cosxdot Then find the value of sin^4x+cos^4x in terms of Ad...

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  10. ABC is an acute angled triangle with circumcenter O and orthocentre H....

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  11. If sintheta=1/2a n dcostheta=-(sqrt(3))/2, then the general value of t...

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  12. In quadrilateral A B C D , if sin((A+B)/2)cos((A-B)/2)+"sin"((C+D)/2)c...

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  13. Find the range of y=sin^3x-6sin^2x+11sinx-6.

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  14. A ladder rest against a wall making an angle alpha with the horizontal...

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  15. Let ABC be an acute angled triangle whose orthocentre is at H. If a...

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  16. The most general value for which tantheta=-1 and costheta=1/(sqrt(2)) ...

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  17. The equation sin^2theta=(x^2+y^2)/(2x y),x , y!=0 is possible if

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  18. Prove that: cos18^0-sin18^0 = sqrt(2)sin27^0

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  19. In a acute angled triangle ABC, proint D, E and F are the feet of the ...

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  20. The number of solutions of the equation cos^2(x+pi/6)+cos^2x-2cos(x+pi...

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