If `A, B, C` are the angles of a right angled triangle, then `(cos^2A+ cos^2B+ cos^2C)` equals

If A,B,C are the angles of a right angled triangle,then (cos^(2)A+cos^(2)B+cos^(2)C) equals

If triangleABC is a right angled at A, then: cos^(2)B + cos^(2)C=

If A,B, C are the angles of a triangle ABC then (cos A+i sin A)(cos B+i sin B)(cos C+i sin C)

In a right angled Delta BC,cos^(2)A+cos^(2)B cos^(2)C=

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 DeltaABC is a right-angled at A, then: cos^2B+cos^2C=

If A,B,C are angles of a triangle, prove that sin((B+C)/2)="cos"A/2

If A,B,C are the angles of a triangle then prove that cos A+cos B-cos C=-1+4cos((A)/(2))cos((B)/(2))sin((C)/(2))

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