Math, asked by shvnbabu3580, 15 hours ago

In triangle abc prove that sin a/2+sin b/3-sin c/2=-1+4cos(π-a/4)cos (π-b/4) sin (π-c/4)

Answers

Answered by 4942
0

Answer:

proved

Step-by-step explanation:

sin

2

A

+sin

2

B

+sin

2

C

=2sin

4

A+B

cos

4

A−B

+sin

2

c

=2sin

4

A+B

cos

4

A−B

+1−2sin

2

4

A+B

[∵A+B+C=Π]

[

2

C

=

2

Π

−(

2

A

+

2

B

)]

∴ 1+2sin(

4

Π

4

C

)[cos(

4

A−B

)−cos(

2

Π

−(

4

A+B

))]

⇒1+2sin(

4

Π

4

C

)2sin(

4

Π

4

A

)sin(

4

Π

4

B

)

⇒1+4sin

4

Π−C

sin

4

Π−A

sin

4

Π−B

(proved)

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