Just remember the quadrants where a particular trigonometric ratio is positive. We know that
In First quadrant : all trigonometric ratios are positive
In second quadrant : Sine and co-secant are positive and rest all trigonometric ratios are negative
In Third quadrant : tangent and cotangent are positive and rest all trigonometric ratios are negative
In Fourth quadrant : cosine and secant are positive and rest all trigonometric ratios are negative
I think that should help you out.