Let $f: R \rightarrow R$ be defined by $f(x)=\left\{\begin{array}{l} If f has a local minimum at $x=-1$, then a possible value of $k$, is |
-1/2 -1 1 0 |
-1 |
If $f(x)$ has a local minimum at $x=-1$, then $\lim\limits_{x \rightarrow-1^{+}} f(x)=\lim\limits_{x \rightarrow-1^{-}} f(x)$ $\Rightarrow \lim\limits_{x \rightarrow-1^{+}} 2 x+3=\lim\limits_{x \rightarrow-1^{-}} k-2 x$ $\Rightarrow -2+3=k+2 \Rightarrow k=-1$ |