Question 953481


{{{x^2/49+y^2/64=1}}}

{{{a^2=49}}}=>{{{a=7}}}

{{{b^2=64}}}=>{{{b=8}}}

The formula generally associated with the focus of an ellipse is {{{b^2= a^2 − c^2}}} where {{{c}}} is the distance from the focus to vertex.

{{{b^2= a^2 − c^2}}}

{{{64= 49 − c^2}}}

{{{c^2=  64-49}}}

{{{c^2=  15}}}

{{{c= sqrt( 15)}}} or {{{c=- sqrt( 15)}}}

so, answer is: Foci (0,+-sqrt 15)