Question

Find equation of ellipse, If foci $(\pm 3,0),a=4$.

Answer 1

Foci$=(\pm 3,0)$,

$a=4$

$c=3$

$b^2=a^2-c^2$

$=4^2-3^2$

$=16-9$

$b^2=7$

Equation of ellipse: $\frac{x^2}{a^2}+\frac{y^2}{b^2}=1$

$\frac{x^2}{16}+\frac{y^2}{7}=1$.