$6-13.$ Draw the influence lines for $($a$)$ the moment at $\backslash ($ C $\backslash ),($b$)$ the shear just to the right of the support at $\backslash ($ B $\backslash ),$ and $($c$)$ the vertical reaction at $\backslash ($ B $\backslash ).$ Solve this problem using the basic method of Sec. $6\mathrm{.}1.$ Assume $\backslash ($ A $\backslash )$ is a pin and $\backslash ($ B $\backslash )$ is a roller.