Question 2: Analysis of the ellipse focal length formula C: When the focal coordinate is on the X axis, c== 1, and when the focal coordinate is on the Y axis, c== 1, from which the value of the real number m can be obtained. Solution: 2c = 2, ∴ C = 1. When the focal coordinate is on the x axis.
Question 3: How to find the focal length of an ellipse is very simple. Put it between two points with a compass, and then there is O.
Question 4: Given the focal length of an ellipse, how to solve the elliptic equation is insufficient. You can only find the ratio of the long and short semi-shafts, but you can't find the specific values of the long and short semi-shafts.
Question 5: The focal length of the ellipse is, the focal coordinate is ... Problem analysis: the ellipse is in the middle, so the focal length and focal point are on the X axis. Focus Note: The focal position and basic quantity can be known from the elliptic equation, and then the focal length can be determined from the available values.