Question 747274
The formula to determine the focus of a parabola is just the Pythagorean theorem. {{{c}}} is the distance to the focus

{{{c^2 =a^2 + b^2}}}

given: {{{x^2/16-y^2/4=1}}}; so, {{{a^2=16}}} =>{{{a=4}}} and {{{a=-4}}}

and {{{b^2=4}}} =>{{{b=2}}} and {{{b=-2}}}

then

{{{c^2 =4^2 + 2^2}}}

{{{c^2 =16 +4}}}

{{{c^2 =20}}}

{{{c=sqrt(20)}}}

{{{c=2sqrt(5)}}}

since foci at ({{{c}}},{{{0}}}) => ({{{2sqrt(5)}}},{{{0}}})


answer is: A. (2√5, 0)