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If cosA + cosB =4sin^(2)(C/2), then...

If cosA + cosB `=4sin^(2)(C/2)`, then

A

`2sinB = sinA + sinC`

B

`cos C = 1-r/R`

C

`cosA + cosB = (2r)/R`

D

a,c,b are in A.P.

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AAKASH INSTITUTE-TRIGNOMETRIC FUNCTIONS -Section-C (Objective Type Questions More than one options are correct )
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