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Prove that bc cos^(2).(A)/(2) + ca cos^(...

Prove that `bc cos^(2).(A)/(2) + ca cos^(2).(B)/(2) + ab cos^(2).(C)/(2) = s^(2)`

A

`(s-a)^(2)`

B

`(s-b)^(2)`

C

`(s-c)^(2)`

D

`s ^(2)`

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ARIHANT MATHS-PROPERTIES AND SOLUTION OF TRIANGLES -Exercise For Sesssion 2
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  2. In any Delta ABC, If cot ""A/2 , cot ""B/2 ,cot ""C/2 are in AP, t...

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  3. In any DeltaABC,("tan"(A)/(2)-"tan"(B)/(2))/("tan"(A)/(2)+"tan"(B)/(2)...

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  4. Prove that bc cos^(2).(A)/(2) + ca cos^(2).(B)/(2) + ab cos^(2).(C)/(2...

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  5. In a Delta ABC, if cos A+cos B=4 sin^(2)((C)/(2)), then a,b,c are in ...

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  6. In a triangle ABC, if b^2 + c^2 = 3a^2, then cotB + cotC-cotA is equal...

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  7. In any Delta ABC, ((b-c)/(a))cos^(2)((A)/(2))+((c-a)/(b))cos ^(2)((b )...

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  8. In a DeltaABC, the tangent of half the difference of two angle is one-...

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  9. If in a triangle a cos^(2).(C)/(2) + c cos^(2).(A)/(2) = (3b)/(2), the...

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  10. In the adjacent figure 'P' is any interior point of the equilateral tr...

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  11. If c^(2) = a^(2) + b^(2), then prove that 4s (s - a) (s - b) (s - c) =...

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  12. The number of possible angle ABC in which BC =sqrt11cm, CA=sqrt13cm an...

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  13. If two sides a, b and the angle A be such that two triangles are forme...

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  14. If in a DeltaABC, sin A =sin^(2) B and 2 cos ^(2)A=3 cos ^(2) B, then ...

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  15. If a cos A =b cos B, then the triange is

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  16. Point D,E are taken on the side BC of an acute angled triangle ABC,, s...

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  17. If the base angles of triangle are 22 1/2a n d112 1/2 , then prove tha...

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  18. In a DeltaABC, a =1 and the perrimeter is six times the AM of the sine...

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  19. In a DeltaABC, if median AD is perpendicular to AB, the tan A+2 tan B ...

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  20. The product of the sines of the angles of a triangle is p and the prod...

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