Question 1046129
In the 3rd qudrant,
sin is negative ( -/+ )
cos is negative ( -/+ )
tan is positive ( -/- )
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{{{ sin( theta ) = -1/2 }}}
and
{{{ cos( theta ) = -sqrt( 1 - sin^2( theta ) ) }}}
and
{{{ tan( theta ) = sin( theta ) / cos( theta ) }}}
{{{ tan( theta ) = -sin( theta ) / (-sqrt( 1 - sin^2( theta ) )) }}}
{{{ tan( theta ) = ( -1/2) / ( -sqrt(  1 - 1/4 ) ) }}}
{{{ tan( theta ) = ( 1/2 ) / sqrt( 3/4 ) }}}
{{{ tan( theta ) = ( 1/2 )*( 2/sqrt(3) ) }}}
{{{ tan( theta ) = 1 / sqrt(3) }}}
( note the tan in 3rd quadrant must be positive )