Question 436283
Since b>a, we have {{{c^2=b^2-a^2}}}, substitute a=4 and b=6,

{{{c^2=36-16=20}}} Thus, {{{c=2sqrt(5)}}} and {{{c=-2sqrt(5)}}}

Therefore the foci of our ellipse will be: (0,{{{2sqrt(5)}}}) and 

(0, {{{-2sqrt(5)}}}).