Question

If A, B, C are the interior angles of triangle ABC then show that

sin(B+c/2) = cosA/2

Answer it fast I have board exam tomorrow..... Plz

Answer 1

Answer:

Step-by-step explanation:

take LHS,

sin(B+C/2)

=cos(90-(B+C/2)(since,sin90-a=cosa)

now taking the angles of both sides,

b+c/2=A/2

Answer 2

Answer:

Step-by-step explanation:

A+B+C=180

A=180-(B+C) 1

Sin(b+c/2) =cos(a/2)

Lhs

Cos(90-(b+c/2))

Cos(180-(b+c) /2)

Cos(a/2) =

Proved