The function $f(x)=\left\{\begin{array}{cc}\frac{\sqrt{1+p x}-\sqrt{1-p x}}{x}, & -1 \leq x<0, \\ \frac{2 x+1}{x-2}, & 0 \leq x \leq 1,\end{array}\right.$ is continuous in the interval [-1, 1], then p is equal to |
1 $-\frac{1}{2}$ $\frac{1}{2}$ -1 |
$-\frac{1}{2}$ |
$f(x)=\left\{\begin{array}{cc}\frac{\sqrt{1+p x}-\sqrt{1-p x}}{x}, & -1 \leq x<0, \\ \frac{2 x+1}{x-2}, & 0 \leq x \leq 1,\end{array}\right.$ Checking at 0 $\lim\limits_{x \rightarrow 0} \frac{\sqrt{1+p x}-\sqrt{1-p x}}{x} \times \frac{\sqrt{1+p x}+\sqrt{1-p x}}{\sqrt{1+p x}+\sqrt{1-p x}}$ $=\lim\limits_{x \rightarrow 0} \frac{2 p}{\sqrt{1+p x}+\sqrt{1-p x}}=p$ so $f(0)=\frac{2(0)+1}{0-2}=\frac{-1}{2}$ so $p = \frac{-1}{2}$ Option: B |