+36916 sin (- theta) = - sin (x) so sin x = 1/6
tan = sin / cos = 1/6 / cos = - sqrt35/35 solve for cos
cos = 1/6 * (-35/sqrt35)
= -35 sqrt35 /210 ( does not match any of your answers....did you enter the Q correctly?? 
)
OoOps ...as Alan has pointed out...it DOES match oe of the choices !
1/6 * -35/sqrt35 = - sqrt35/6
Thanx, Alan !!!
