$c_{12}=cos({}_{12})=cos({}_{21})$ and the result of $co{s}^{-1}(c_{12}).$ Choose the graph as usual. Finally, be sure to keep angles between $-180$ and $+180.$

First Example. Given $x_1=0\mathrm{.}38823lbf,Y_1=1\mathrm{.}44889lbf,x_2=1\mathrm{.}50000lbf,$ and $Y_2=0\mathrm{.}00000lbf,$ declare the unknown values

$\backslash$table$[[x_R,1288823,($lbf$)$