# Talk:Derivation of the Routh array

WikiProject Systems (Rated Start-class, Mid-importance)
Start  This article has been rated as Start-Class on the project's quality scale.
Mid  This article has been rated as Mid-importance on the project's importance scale.

Isn't the left hand side of eqns 13 and 14 supposed to be only${\displaystyle \theta (x)}$ (no index ${\displaystyle r_{i}}$)? (Havresylt (talk) 05:45, 19 October 2009 (UTC))