Which trigonometric function is positive in which quadrant; this will tell you!

The basic trigonometry dictates that the signs of trigonometric functions depend on the signs of the coordinates of the points on the terminal side of the angle. There are eight places where the terminal side of the angle can lie.

In the first quadrant, where x and y coordinates are all positive, all six trigonometric functions have positive values. In the second quadrant, only sine and cosecant (the reciprocal of sine) are positive. In the third quadrant, only tangent and cotangent are positive. Finally, in the fourth quadrant, only cosine and secant are positive.