In Triangle ABC. Line joining the Circum-centre and Ortho-centre is Parallel to side AC, then value of tan A tan C is equal to
3
Distance of circum-centre from side AC=R cos B and
distance of ortho-centre from side AC=2R cos A cos C
⇒ R cos B=2R cos A.cos C
⇒ -cos(A+C)=2cos A.cos C
⇒ sin A. sin C=3cos A.cos C
⇒ tan A.tan C=3