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In triangle ABc, if A-B=120^(@) and R=8r...

In triangle ABc, if `A-B=120^(@) and R=8r` where R r have their usual meaning then cos C equals

A

`3//4`

B

`2//3`

C

`5//6`

D

`7//8`

Text Solution

Verified by Experts

The correct Answer is:
D
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