Question

ln a triangle ABC prove that 2(b cos power 2c/2 + c cos power 2 B/2 ) =a+b+c.

Answer 1

2{bc9s^2c/2+ccos^2b/2}
=2{b(1+cosc/2)+c(1+cosb/2)}
=2/2{b+bcosc+c+c cos b+c}
=b+c+bcosc+ccosb
=b+c+a
=,a+b+c
HENCE PROVED