******************* This email originates from outside Imperial. Do not click on links and attachments unless you recognise the sender. If you trust the sender, add them to your safe senders list https://spam.ic.ac.uk/SpamConsole/Senders.aspx to disable email stamping for this address. ******************* Dear All, I am a user of Nektar ++, and learning its foundation with Sherwin's book, Spectral hp element method for CFD [2ed]. I have a small question, while I study the book. When the book explains the Gauss-Lobatto-Legendre formula for integration (pg.61) and differentiation (pg 68), xi are the roots of Jocobi polynomial. However, in other references ( https://en.wikipedia.org/wiki/Gaussian_quadrature), they are the roots of Legendre polynomial. Which one is right? or both are correct? Please let me be clear about that. Thank you. Dongmyung Suh