Question

In triangle ABC, if a 2cos A=sin B cosec c then....​

Answer 1

As we know that

sinC

sinB

=

c

b

cosA=

2bc

b

2

+c

2

−a

2

Given 2cosA=sinBcosec C

⟹2cosA=

sinC

sinB

⟹2×

2bc

b

2

+c

2

−a

2

=

c

b

⟹b

2

+c

2

−a

2

=b

2

⟹c

2

=a

2

⟹c=a