298* falls in quadrant 4 is 0* is the positive x-axis. In quadrant 4, cos is positive. Therefore, we simply need to calculate the acute angle,x, that correlates to 298*.
360 = 298 + x
62 = x
Therefore, we have :
cos(298*) = cos(62)
In case you need to know :
sin(298*) = - sin (62)
tan(298*) = - tan (62)
Since both sin and tan are negative in the fourth quadrant.