How can I know if Rahu is beneficial in a horoscope

Rahu is at his influential best when he or Ketu are positioned in angles (1,4,7,10) and are associated with Lord of the trine (1,5,9) and vice versa. This by itself forms winning yogas or recipes for success. Although the native with Rahu in second house tends to obsess about wealth, he finally manages to achieve affluence.