Prove that `a cos^(2)(A/2)+b cos^(2)(B/2)+c cos^(2)(C/2)=s+(Delta)/(R)`

Show that a cos^(2)[(A)/(2)]+b cos^(2)[(B)/(2)]+c cos^(2)[(C)/(2)]=s+(D)/(R)

In Delta ABC prove that cos^(2)((A)/(2))+cos^(2)((B)/(2))+cos^(2)((C)/(2))=2+(r)/(2R)

If A+B+C=pi then prove that cos^(2)((A)/(2))+cos^(2)((B)/(2))-cos^(2)((C)/(2))=2cos((A)/(2))cos((B)/(2))sin((C)/(2))

If A+B+C=180^0 , prove that : cos^2(A/2) + cos^2(B/2) - cos^2(C/2) = 2cos(A/2) cos(B/2) sin( C/2)

Prove that in triangle ABC , cos^(2)A + cos^(2)B + cos^(2)C lt 3/4 .

In any Delta ABC, prove that: (cos^(2)((A)/(2)))/(a)+(cos^(2)((B)/(2)))/(b)+(cos^(2)((c)/(2)))/(c)=(s^(3))/(abc)

In a triangle ABC,cos^(2)A+cos^(2)B+cos^(2)C=

In Delta ABC , prove that (b - c)^(2) cos^(2) ((A)/(2)) + (b + c)^(2) sin^(2) ((A)/(2)) = a^(2) .

In triangle ABC,prove that cos((A)/(2))+cos((B)/(2))+cos((C)/(2))=4(cos(pi-A))/(4)(cos(pi-B))/(4)(cos(pi-C))/(4)

Prove that : (abc)/(s) cos (A)/(2) cos (B)/(2) cos (C )/(2) = triangle .