What is the sum of focal radii of any point on an ellipse equal to ?

What is the sum of the focal distances of a point of an ellipse x^(2)/a^(2)+y^(2)/b^(2)=1 ?

Consider the ellipse E_1, x^2/a^2+y^2/b^2=1,(a>b) . An ellipse E_2 passes through the extremities of the major axis of E_1 and has its foci at the ends of its minor axis.Consider the following property:Sum of focal distances of any point on an ellipse is equal to its major axis. Equation of E_2 is

Consider the ellipse E_1, x^2/a^2+y^2/b^2=1,(a>b) . An ellipse E_2 passes through the extremities of the major axis of E_1 and has its foci at the ends of its minor axis.Consider the following property:Sum of focal distances of any point on an ellipse is equal to its major axis. Equation of E_2 is

Prove that the sum of the focal distance of any point on the ellipse is constant and is equal to the length of the major axis.

Find the eccentricity and equations of the directrices of the ellipse (x^(2))/(100) + (y^(2))/ (36) = 1 . Show that the sum of the focal distances of any point on this ellipse is constant .

Theorem: The sum of the focal diatances of any point on an ellipse is constant and equal to the length of the major axis of the ellipse.

Consider the parabola y=x^(2)+7x+2 and the straight line y=3x-3 . The sum of the focal distances of a point on an ellipse is constant and equal to the

Find the sum of the focal distances of any point on the ellipse 9x^2+16 y^2=144.