Question
Question: The derivative of \(f(x) = |x|^{3}\) at \(x = 0\) is...
The derivative of f(x)=∣x∣3 at x=0 is
A
0
B
1
C
–1
D
Not defined
Answer
0
Explanation
Solution
$f(x) = \left{ \begin{matrix} x^{3} & , & x \geq 0 \
- x^{3} & , & x < 0 \end{matrix} \right.\ andf^{'}(x) = \left{ \begin{matrix} 3x^{2} & , & x \geq 0 \
- 3x^{2} & , & x < 0 \end{matrix} \right.\ $
f′(0+)=f′(0−)=0