Problem $3$

$(25$ points$)$

Draw the following influence lines along member $\backslash (\backslash$boldsymbol$\{$A B C$\}\backslash )$ of the frame in Figure $3$:

$(1)$ vertical reaction force at support $\backslash (\backslash$boldsymbol$\{$D$\}\backslash ),(2)$ vertical reaction force at support $\backslash (\backslash$boldsymbol$\{$C$\}\backslash ),(3)$ shear force at point $\backslash (\backslash$boldsymbol$\{$E$\}\backslash ),$ and $(4)$ bending moment at point $\backslash (\backslash$boldsymbol$\{$F$\}\backslash ).($Set the origin at point $\backslash (\backslash$boldsymbol$\{$A$\}\backslash ))$

Figure $3$