Q. Write an equation for an ellipse centered at the origin, which has foci at (0,±15) and co-vertices at (±8,0).
Ellipse Orientation: We have:Foci: (0,±15)Co-vertices: (±8,0)Since the foci are on the y-axis, this indicates a vertical orientation for the ellipse.
Identify c: We have:Center (h,k): (0,0)Foci: (0,±15)Identify the value of c (the distance from the center to a focus).c=(0−0)2+(15−0)2=02+152=225=15
Identify b: We have:Center (h,k): (0,0)Co-vertices: (±8,0)Identify the value of b (the distance from the center to a co-vertex).b=(8−0)2+(0−0)2=82+02=64=8
Calculate a: We know the relationship between a, b, and c for an ellipse with a vertical orientation is c2=a2−b2. We have already found c=15 and b=8. Now we solve for a. a2=c2+b2=152+82=225+64=289a=289=17
Standard Form: We know:(h,k)=(0,0)a=17b=8The standard form of the ellipse with a vertical orientation is:b2(x−h)2+a2(y−k)2=1Substitute the values of h, k, a, and b:82(x−0)2+172(y−0)2=164x2+289y2=1
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