Question 1158031
(1)
{{{ cos( 11pi/6 ) }}}
{{{ 11pi/6 = 12pi/6 - pi/6 }}}
{{{ 11pi/6 = 2pi - pi/6 }}}
This is in the 4th quadrant & the cos is positive
{{{ cos( 11pi/6 ) = sqrt(3) / 2 }}}
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(2) 
{{{ cot( 5pi/4 ) }}}
{{{ 5pi/4 = 4pi/4 + pi/4 }}}
{{{ 5pi/4 = pi + pi/4 }}}
This is in the 3rd quadrant & cot is positive (-) / (-) = (+)
{{{ cot( 5pi/4 ) = 1/1 }}}
{{{ cot( 5pi/4 ) = 1 }}}
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(3)
{{{ sec( 4pi/3 ) }}}
{{{ 4pi/3 = 3pi/3 + pi/3 }}}
{{{ 4pi/3 = pi + pi/3 }}}
This its in the 3rd quadrant & the sec is negative
{{{ sec( 4pi/3 ) = 2/(-1) }}}
{{{ sec( 4pi/3 ) = -2 }}}
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