Introduction
The Unit Circle is a measurement of 2Π radians or 360 degrees. It is divided into four equal sections called quadrants. The points along the outline of the circle are called coordinate points and are arranged as (x, y). In Quad I, both coordinate points are positive. In Quad II, y is positive and X is negative. In Quad III, both coordinate points are negative. In Quad IV, Y is negative and X is positive.
Sine= Y
Cosine= X
Tangent= y/x
Keeping this in mind, in Quad I, sine, cosine and tangent are all positive. In Quad II, sine is positive, cosine and tangent are both negative. In Quad III, tangent is positive and sine and cosine are both negative. In Quad IV, cosine is positive, sine and tangent are negative. Tangent is negative when sine and cosine have opposite signs; meaning when one is positive and the other is negative. Tangent is positive when they have the same signs.
Sine= Y
Cosine= X
Tangent= y/x
Keeping this in mind, in Quad I, sine, cosine and tangent are all positive. In Quad II, sine is positive, cosine and tangent are both negative. In Quad III, tangent is positive and sine and cosine are both negative. In Quad IV, cosine is positive, sine and tangent are negative. Tangent is negative when sine and cosine have opposite signs; meaning when one is positive and the other is negative. Tangent is positive when they have the same signs.
