The equation of an ellipse is given below.25(x−3)2+169(y+1)2=1What are the foci of this ellipse?Choose 1 answer:(A) (3,−13) and (3,11)(B) (9,1) and (−15,1)(C) (−12,−1) and (15,−1)(D) (−3,13) and (−3,−11)
Q. The equation of an ellipse is given below.25(x−3)2+169(y+1)2=1What are the foci of this ellipse?Choose 1 answer:(A) (3,−13) and (3,11)(B) (9,1) and (−15,1)(C) (−12,−1) and (15,−1)(D) (−3,13) and (−3,−11)
Identify center and axes lengths: Identify the center and lengths of the semi-major and semi-minor axes.The standard form of an ellipse is (x−h)2/a2+(y−k)2/b2=1, where (h,k) is the center of the ellipse, a is the length of the semi-major axis, and b is the length of the semi-minor axis. For the given ellipse, h=3, k=−1, a2=25, and b2=169. Therefore, a=5 and b=13.
Determine major axis: Determine which axis is the major axis.Since b > a, the major axis is along the y-axis. This means that the foci will be vertically aligned with the center of the ellipse.
Calculate distance to foci: Calculate the distance c from the center to each focus. The distance c is found using the equation c2=b2−a2. Plugging in the values, we get c2=169−25=144. Taking the square root gives us c=12.
Find foci coordinates: Find the coordinates of the foci.The foci are located at (h,k±c) since the major axis is vertical. Substituting the values, we get the foci at (3,−1±12). This gives us the two points (3,−1+12) and (3,−1−12), which simplifies to (3,11) and (3,−13).
More problems from Find properties of ellipses from equations in general form