About: http://webisa.webdatacommons.org/195783724

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	The idea is that we know there is a formula that relates $\cos(2x)$ to either $\cos(x)$ or $\sin(x)$ but people tend not to have the exact form on immediate recall.
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com