Extra Credit Prove xh2a2 yk2b2 1 Given center hk Foci h p
     Extra Credit Prove : (x-h)^2/a^2 + (y-k)^2/b^2 = 1 Given: center (h,k) Foci (h plusminusc, k Vertices (hplusminusa, k) 
  
  Solution
Solution :
We know that the equation of an ellipse is
(x-h)^2/a^2+(y-k)^2/b^2=1.
Centre the point (h, k).
Then coordinate of center become (x-h, y-k)=(0,0)
Or. x =h and y=k.
And foci (+-a, 0) =(x-h, y-k)
Or. x=+-a+h, y = k
Thus foci are (+-a+h, k).

