Exercise $4$: $(2$ points$)$

The W$200$x$59$ A$-36$ steel column shown is fixed at its base and braced at the top so that it is fixed from displacement, yet free to rotate about the y$-$y axis. Also, it can sway to the side in the y$-$z plane. Using the secant formula:

a$)(2$ points$)$ determine the maximum eccentric load the column can support before it either begins to buckle or the steel yields