Question

[
begin{array}{l}
2 cos A=frac{sin B}{sin C}
2 sin C cos A=sin B
sin (C+A)+sin (C-A)=sin A
sin (180-A)+sin (B-c)=sin A
sin A+sin (B-C)=8 pi A
sin (B-C)=0
B-C=0
B=C
end{array}
]
hence 2 sider are equal it in incelen ( A ).

# 6. If 2 cos A = SinB then show that the triangle is isosceles. sin C

Solution