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If 1/(a+c)+ 1/(b+c) = 3/(a+b+c) Then p...

If `1/(a+c)+ 1/(b+c) = 3/(a+b+c)`
Then prove C = `60^@`.

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MBD PUBLICATION-TRIGONOMETRIC FUNCTIONS-QUESTION BANK
  1. In Delta ABC prove that a^3cos(B-C) + b^3cos(C-A) + c^3 cos(A-B) = 3...

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  2. In Delta ABC prove that a(cosB + cosC) = 2(b+c) sin^2(A/2)

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  3. In Delta ABC prove that (b+c-a) tan A/2 = (c+a-b) tanB/2 = (a+b-c) t...

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  4. In Delta ABC prove that (b+c-a)(cotB/2 + cot C/2) = 2a cotA/2

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  5. In Delta ABC prove that (a-b)^2 cos^2(C/2) + (a+b)^2 sin^2(C/2)= c^...

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  6. In Delta ABC prove that 1-tan(A/2) tan (B/2) = c/s

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  7. In Delta ABC prove that (b-c)cot(A/2) + (c-a)cot(B/2) + (a-b)cot(C/2...

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  8. In Delta ABC prove that cotA + cotB + cotC = (a^2 + b^2 + c^2)/(4Del...

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  9. If 1/(a+c)+ 1/(b+c) = 3/(a+b+c) Then prove C = 60^@.

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  10. If a = 2b and A = 3B find the measure of the angle of the triangle.

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  11. If a^4 + b^4 + c^4 = 2c^2 (a^2 + b^2), prove that angle ACB = 45^@ o...

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  12. If x^2 + x + 1, 2x+1 and x^2 - 1 are lengths of sides of a triangle, t...

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  13. If cosB = (sinA)/(2sinC) prove that the triangle is isosceles.

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  14. If a tan A + b tanB = (a+b) tan ((A+B)/2) prove that the triangle is i...

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  15. If (cosA + 2cosC) : (cosA + 2cosB) = sinB : sinC prove that the tria...

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  16. If cos A = sinB - cosC prove triangle is right angled.

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  17. If a^2,b^2,c^2 being A.P prove that cotA,cotB,cotC are also In A.P.

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  18. If sinA : sinC = sin(A-B): sin(B-C) prove that a^2,b^2,c^2 are in A.P.

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  19. If the side lengths a,b and c are in A.P. then prove that cos ((A-C)...

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  20. If the side lengths a,b and c are in A.P. prove that cot (A/2),cot (...

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