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The sides a, b, c of a triangle ABC are ...

The sides a, b, c of a triangle ABC are in arithmetic progression and 'a' is the smallest side. What is cos A equal to ?

A

`(3c-4b)/(2c)`

B

`(3c-4b)/(2b)`

C

`(4c-3b)/(2c)`

D

None of these

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ARIHANT MATHS-PROPERTIES AND SOLUTION OF TRIANGLES -Exercise For Sesssion 1
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  5. If cot ""A/2 =(b+c)/(a),then DeltaABC is

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  6. If in a DeltaABC, (a^(2)-b^(2))/(a ^(2)+b^(2))=(sin (A-B))/(sin (A+B))...

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  7. In any triangle A B C , prove that: (a^2sin(B-C))/(sinB+s in C)+(b^2si...

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  11. In a Delta ABC, (a+b+c) (b+c-a) = gamma bc if

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  12. If : a = 9, b = 8 and c = x satisfies 3 cos C = 2, then : x =

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  13. In DeltaABC, if sin^2 A+ sin^2 B = sin^2 C, then the triangle is

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  14. The lengths of the sides of a triangle are alpha-beta, alpha+beta and ...

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  16. The sides a, b, c of a triangle ABC are in arithmetic progression and ...

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  17. In a DeltaABC, a ^(2) cos 2B+b^(2) cos 2A+2ab cos (A-B)=

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  18. In any DeltaABC, 2 [bc cos A + ca cos B+ ab cos C]=

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