Consider the following statements: 1. The function f(x) = | x | is not differentiable at x = 1 2. The function f(x) = ex is differentiable at x = 0. Which of the above statements is/are correct?
Consider the following statements: 1. The function f(x) = | x | is not differentiable at x = 1 2. The function f(x) = ex is differentiable at x = 0. Which of the above statements is/are correct? Correct Answer 2 only
Concept:
Differentiability of a function:
We will define the differentiability of the function with the help of its graph. If a graph of a function is smooth everywhere then the function is said to be differentiable everywhere in the xy - plane.
If the function has a sharp edge or a vertical asymptote (tangent) to the curve then the function is not differentiable at that point.
Calculation:
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Observe the graph of the function f(x) = |x|.
At x = 1 the curve is smooth and thus the function is differentiable at x = 1.
On the other hand the function is not differentiable at x = 0 as it has a corner at x = 0.
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Observe the graph of the function f(x) = ex.
At x = 0 the curve is smooth so it is differentiable at x = 0.
Thus only the second statement is true.