(1) (1-cos(x))/(sin(x))(sin(x))/(1+cos(x))=4,
(1-cos(x))/(1+cos(x))=4 because sin(x) cancels out.
1-cos(x)=4+4cos(x), 5cos(x)=-3, cos(x)=-⅗, x=2.2143 radians approx (126.87°), or 4.0689 radians (233.13°).
(2) (1+cos(x))/(sin(x))(sin(x))/(1-cos(x))=4,
1+cos(x)=4-4cos(x), 5cos(x)=3, cos(x)=⅗, x=0.9273 radians (53.13°), or 5.3559 radians (306.87°).