Question 1062292
<pre>
                      SPEED          TIME       DISTANCE

FIRSTCAR               56           {{{t}}}          {{{56t)}}}
SECCAR                 54            {{{t+1/6}}}     {{{54*(t+1/6)}}}
DISTANCE 112 Degrees                            Law Of Cosines
</pre>


Careful with Law of Cosines.  The angle between the cars is 112 degrees and the cosine must be the negative value.  {{{-cos(112-90)=-cos(22)=-0.92718=cos(112)}}}


Distance d between the cars any time t is  
{{{(56t)^2+(54(t+1/6))^2-2(56t)(54(t+1/6))(-0.92718)=d^2}}}


{{{highlight*d=sqrt((56t)^2+(54(t+1/6))^2-2(56t)(54(t+1/6))(-0.92718))}}}
That is the formula.  Simplify any way you like, and then substitute {{{t=1/2}}} to evaluate d.