22. (Total: 16 points; Part 1: 4 points; Part 2: 6 points; Part 3: 6 points) Given the ellipse $C: \frac{x^2}{m^2} + y^2 = 1$ (constant $m > 1$), $P$ is a moving point on curve $C$, $M$ is the right vertex of curve $C$, and the fixed point $A$ has coordinates $(2, 0)$ (1) If $M$ coincides with $A$, find the coordinates of the foci of curve $C$; (2) If $m = 3$, find the maximum and minimum values of $|PA|$; (3) If the minimum value of $|PA|$ is $|MA|$, find the range of the real number $m$.
(10 marks) As shown in the figure, $D$ and $E$ are points on sides $AB$ and $AC$ of $\triangle ABC$ respectively, and do not coincide with the vertices of $\triangle ABC$. Given that the length of $AE$ is $m$, the length of $AC$ is $n$, and the lengths of $AD$ and $AB$ are the two roots of the equation $x ^ { 2 } - 14 x + m n = 0$ in $x$.
22. (Total: 16 points; Part 1: 4 points; Part 2: 6 points; Part 3: 6 points)\\
Given the ellipse $C: \frac{x^2}{m^2} + y^2 = 1$ (constant $m > 1$), $P$ is a moving point on curve $C$, $M$ is the right vertex of curve $C$, and the fixed point $A$ has coordinates $(2, 0)$\\
(1) If $M$ coincides with $A$, find the coordinates of the foci of curve $C$;\\
(2) If $m = 3$, find the maximum and minimum values of $|PA|$;\\
(3) If the minimum value of $|PA|$ is $|MA|$, find the range of the real number $m$.