2.2 Basic Concepts

In Class XI, we have studied trigonometric functions, which are defined as follows: sine function, i.e., sine: \(R \rightarrow [-1, 1]\) cosine function, i.e., cos: \(R \rightarrow [-1, 1]\) tangent function, i.e., tan: \(R - \{x: x = (2n+1)\frac{\pi}{2}, n \in Z\} \rightarrow R\) cotangent function, i.e., cot: \(R - \{x: x = n\pi, n \in Z\} \rightarrow R\) secant function, i.e., sec: \(R - \{x: x = (2n+1)\frac{\pi}{2}, n \in Z\} \rightarrow R - (-1, 1)\) cosecant function, i.e., cosec: \(R - \{x: x = n\pi, n \in Z\} \rightarrow R - (-1, 1)\)