The eccentric angles of extremities of a focal chord (other than Major axis) of an ellipse x2a2+y2b2=1 are θ1 and θ2. If the eccentricity of the ellipse are e1 and e2 for the conditions a>b and b>a respectively, then cos2(θ1−θ22)(1e21+1e22) is

The eccentric angles of extremities of a focal chord (other than Major

1.	The eccentric angles of extremities of a focal chord (other than Major axis) of an ellipse x2a2+y2b2=1 are θ1 and θ2. If the eccentricity of the ellipse are e1 and e2 for the conditions a>b and b>a respectively, then cos2(θ1−θ22)(1e21+1e22) is
Answer» The eccentric angles of extremities of a focal chord (other than Major axis) of an ellipse $\frac{x^{2}}{a^{2}} + \frac{y^{2}}{b^{2}} = 1$ are $θ_{1}$ and $θ_{2}$ . If the eccentricity of the ellipse are $e_{1}$ and $e_{2}$ for the conditions $a > b$ and $b > a$ respectively, then ${cos}^{2} (\frac{θ_{1} - θ_{2}}{2}) (\frac{1}{e_{1}^{2}} + \frac{1}{e_{2}^{2}})$ is