Question 1058898
The cosine function is negative in the 
2nd and 3rd quadrants
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In the 2nd quadrant, the angle is 
{{{ pi - pi/6 = ( 5*pi )/6 }}} or {{{ 150 }}} degrees
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In the 3rd quadrant, the angle is:
{{{ pi + p/6 = ( 7*pi )/6 }}} or {{{ 210 }}} degrees
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So, {{{ x = ( 5*pi )/6 }}} and {{{ ( 7*pi )/6 }}}