Question 754163
find the equation given foci (3,0) and (-3,0) and sum of focal radii 10
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Given ellipse has a horizontal major axis and origin at (0,0)
Its standard form: {{{x^2/a^2+y^2/b^2}}}, a>b
c=3 (distance from center to foci)
c^2=9
given sum of focal radii=10=2a
a=5
a^2=25
c^2=a^2-b^2
b^2=a^2-c^2=25-9=16
Equation of given ellipse:
 {{{x^2/25+y^2/16}}}