Question 1002283
{{{tan(2*theta)=sin(2*theta)/cos(2*theta)=3/7}}}, can be quadrant 1 or quadrant 3.


{{{sec(2*theta)=1/cos(2*theta)=6}}};
{{{cos(2*theta)=1/6}}}, can mean quadrant 1 or quadrant 4.


{{{2*theta}}} must be in quadrant 1.
{{{2*theta=arccos(1/6)}}}
{{{2*theta=80.4*degrees}}}
{{{highlight(theta=40.2*degrees)}}}