If $f(x) = |2x+5|, $ then $f(x)$ is : |
Discontinuous at $x=\frac{-5}{2}$ Continuous and differentiable at $x=\frac{-5}{2}$ Discontinuous and non-differentiable at $x=\frac{-5}{2}$ Continuous and non differentiable at $x=\frac{-5}{2}$ |
Continuous and non differentiable at $x=\frac{-5}{2}$ |
The correct answer is Option (4) → Continuous and non differentiable at $x=\frac{-5}{2}$ $f(x)=\left\{\begin{matrix}2x+5&x≥-5/2\\-2x-5&x<-5/2\end{matrix}\right.$ $\underset{x→-\frac{5}{2}}{\lim}=0=f(-\frac{5}{2})$ ⇒ f is continuous at $-\frac{5}{2}$ $f'(x)=\left\{\begin{matrix}2&x≥-5/2\\-2&x<-5/2\end{matrix}\right.$ $LHD=-2$, $RHD=2$ $LHD≠RHD$ f is not differentiate at $-\frac{5}{2}$ |