Question 1121656
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I will help you to make your problem easier.



<pre>
    {{{67pi/12}}} = {{{48pi/12}}} + {{{19pi/12}}} = {{{4pi}}} + {{{19pi/12}}}.


{{{4pi}}} is two complete rotations, and geometrically it is the same as the angle of zero radians.


So, your original angle is equivalent to (is the same as)  {{{19pi/12}}} = {{{pi}}} + {{{7pi/12}}}.


Now, if you, as you said, know the unit circle, you can complete the assignment on your own.
</pre>


<U>The lesson to learn from this solution</U> :


<pre>
     When it is needed, extract the integer number of full rotations, i.e. the angle multiple of {{{2pi}}}.
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