Question 1178822
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<pre>

If   cos(x/3) - sin(x/3) = 0,  then

    cos(x/3) = sin(x/3),


which implies

    tan(x/3) = 1.


Hence,  x/3 =  {{{pi/4 + k*pi}}}  and  x = {{{3pi/4 + 3k*pi}}}.


In the interval  [0,2pi) the solution is unique :  x = {{{3pi/4}}}.    <U>ANSWER</U>
</pre>

Solved.