$2\mathrm{.}45$ Two cables tied together at $C$ are loaded as shown. Knowing that the maximum

allowable tension in each cable is $800$ N $,$ determine $($a$)$ the magnitude of the

largest force P that can be applied at $C,($b$)$ the corresponding value of $a.$

Fig. P$2\mathrm{.}45$ and P$2\mathrm{.}46$