[-115A,B,C" .Finfer and "A" and "],[[" -1"cos C,cos beta],[cos C,-1,cos A],[cos B,cos A,-1]=0]

(cos A-cos B+cos C+1)/(cos A+cos B+cos C-1) =

If A , Ba n dC are the angels of a triangle, show that |[-1+cos B, cos C+cos B, cos B],[ cos C+cos A,-1+cos A ,cos A],[-1+cos B,-1+cos A,-1]|=0

If A,B and C are the angles of a triangle, then |[-1+cos B, cos C+ cos B, cos B],[cos C+ cos A,-1+cos A, cos A],[-1+cos B,-1+cos A,-1]|

If A,B,C are the angles of triangle ABC, then the minimum value of |{:(-1,cos C , cos B),(cos C , -1, cos A ) , (cos B , cos A , -1):}| is equal to :

If A, B and C denote the angles of a triangle, then Delta = |(-1,cos C,cos B),(cos C,-1,cos A),(cos B,cos A,-2)| is independent of

If A, B and C denote the angles of a triangle, then Delta = |(-1,cos C,cos B),(cos C,-1,cos A),(cos B,cos A,-2)| is independent of

If A,B,C are the angles of triangle ABC, then the minimum value of |{:(-2,cos C , cos B),(cos C , -1, cos A ) , (cos B , cos A , -1):}| is equal to :

If A,B,C are the angles of triangle ABC, then the minimum value of |{:(-2,cos C , cos B),(cos C , -1, cos A ) , (cos B , cos A , -1):}| is equal to :

Theorem 2:cos2A+cos2B+cos2C=-1-4cos A cos B cos C

(c-b cos A)/(b-c cos A)=(cos B)/(cos C)