Assertion: ellipse's foci | /r/HasProperty | x = a 2 c
Facets:
Source sentences:
text: The foci ( c , 0 ) , {\displaystyle (c,\,0),} ( − c , 0 ) {\displaystyle (-c,\,0)} x = a 2 c {\displaystyle x={\tfrac {a^{2}}{c}}} x = − a 2 c {\displaystyle x=-{\tfrac {a^{2}}{c}}}