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5 votes
5 votes
Is the function
f(x)=√(x) differentiable at x=0 and continuous over R?

User Behrouz Bakhtiari
by
2.6k points

1 Answer

20 votes
20 votes

Answer: No

Step-by-step explanation:

Apply the derivative


f(x) = √(x)\\\\f(x) = x^(1/2)\\\\f'(x) = (1/2)x^(-1/2)\\\\f'(x) = (1)/(2x^(1/2))\\\\f'(x) = (1)/(2√(x))\\\\

Though we run into a problem since f ' (0) is undefined, due to the zero in the denominator.

Therefore, f(x) is not differentiable at x = 0.

The function is continuous, but only on the interval
x \ge 0 and not over the entire set of real numbers R.

User Will Harrison
by
3.2k points