Find standard form of ellipse with vertices (4,0) and (-4,0) And b=1. I know the equation c^2=a^2-b^2 but I can't find a or c. And without a or c I can only plug in b. So can someone help me with this problem and give a good explanation on how I would find a and c so I can figure out how to do the rest of these problems by myself. Please and thank you.