Consider `f(x)=tan^(-1)(sqrt((1+sinx)/(1-sinx))), x in (0,pi/2)dot` A normal to `y=f(x)` at `x=pi/6` also passes through the point: (1) (0, 0) (2) `(0,(2pi)/3)` (3) `(pi/6,0)` (4) `(pi/4,0)`