MathematicsMedium74×since 2004Q3741An ellipse has OBOBOB as semi minor axis, FFF and FFF' its focii and theangle FBFFBFFBF' is a right angle. Then the eccentricity of the ellipse is :A12{1 \over {\sqrt 2 }}21B12{1 \over 2}21C14{1 \over 4}41D13{1 \over {\sqrt 3 }}31Check answerSkip