Graphs of Sine, Cosine and Tangent

Here are some nice graphs to look at ...

Plot of Sine and Cosine Both Sine and Cosine have the same beautiful up-down curve (which repeats every 2π radians, or 360°). And they are like good friends: they follow each other, exactly "π/2" radians, or 90° apart.

Plot of the Tangent Function The Tangent function has a completely different shape ... it goes between negative and positive Infinity, crossing through 0 (every 2π radians, or 360°), as shown on this plot. At right angles (π/2 radians, or 90°), the function is officially undefined, because it could be positive Infinity or negative Infinity.