Let $ \mathbb{R} $ denote the set of all real numbers. Define the function $ f: \mathbb{R} \to \mathbb{R} $ by $$ f(x) = \begin{cases} 2 - 2x^2 - x^2 \sin\left(\frac{1}{x}\right), & \text{if } x \ne 0, \\ 2, & \text{if } x = 0. \end{cases} $$ Then which one of the following statements is TRUE?
f(x) is said to be differentiable at the point x = a, if the derivative f ‘(a) be at every point in its domain. It is given by
Mathematically, a function is said to be continuous at a point x = a, if
It is implicit that if the left-hand limit (L.H.L), right-hand limit (R.H.L), and the value of the function at x=a exist and these parameters are equal to each other, then the function f is said to be continuous at x=a.
If the function is unspecified or does not exist, then we say that the function is discontinuous.