Answer:
Center [tex]= (0,0)[/tex]
Vertices [tex]=(-\sqrt{7},0)\text{ and }(\sqrt{7},0)[/tex]
Foci [tex]=(-2,0)\text{ and }(2,0)[/tex].
Step-by-step explanation:
The standard form of an ellipse is
[tex]\dfrac{x^2}{a^2}+\dfrac{y^2}{b^2}=1[/tex] ...(1)
where, a>b, (0,0) is center, (±a,0) are vertices and (±c,0) are foci.
[tex]c=\sqrt{a^2-b^2}[/tex]
The given equation of ellipse is
[tex]3x^2+7y^2=21[/tex]
Divide both sides by 21.
[tex]\dfrac{3x^2+7y^2}{21}=\dfrac{21}{21}[/tex]
[tex]\dfrac{x^2}{7}+\dfrac{y^2}{3}=1[/tex] ...(2)
On comparing (1) and (2), we get
[tex]a^2=7,b^2=3[/tex]
[tex]a=\sqrt{7},b=\sqrt{3}[/tex]
Now,
[tex]c=\sqrt{a^2-b^2}=\sqrt{7-3}=\sqrt{4}=2[/tex]
Therefore,
Center [tex]= (0,0)[/tex]
Vertices [tex]=(\pm a,0)=(\pm \sqrt{7},0}=(-\sqrt{7},0)\text{ and }(\sqrt{7},0)[/tex]
Foci [tex]=(\pm c, 0)=(\pm 2,0)=(-2,0)\text{ and }(2,0)[/tex].
