The function [tex]f(x)=\left\{\begin{array}{ll}x+1 & \text{if } x\ \textless \ -2 \\ 2x-3 & \text{if } x \geq -2\end{array}\right.[/tex] has a discontinuity at [tex]x=[/tex]



Answer :

To determine where the function [tex]\( f(x) \)[/tex] has a discontinuity, we need to examine the points where the definition of the function changes and match the left-hand limit and the right-hand limit at those points.

The function given is:
[tex]\[ f(x) = \begin{cases} x + 1 & \text{if } x < -2 \\ 2x - 3 & \text{if } x \geq -2 \end{cases} \][/tex]

Let's check the point where the definition changes, which is at [tex]\( x = -2 \)[/tex].

### Left-hand limit:
For the part of the function where [tex]\( x < -2 \)[/tex]:
[tex]\[ \lim_{{x \to -2^-}} f(x) = \lim_{{x \to -2^-}} (x + 1) \][/tex]
Substituting [tex]\( x = -2 \)[/tex]:
[tex]\[ \lim_{{x \to -2^-}} (x + 1) = -2 + 1 = -1 \][/tex]

### Right-hand limit:
For the part of the function where [tex]\( x \geq -2 \)[/tex]:
[tex]\[ \lim_{{x \to -2^+}} f(x) = \lim_{{x \to -2^+}} (2x - 3) \][/tex]
Substituting [tex]\( x = -2 \)[/tex]:
[tex]\[ \lim_{{x \to -2^+}} (2x - 3) = 2(-2) - 3 = -4 - 3 = -7 \][/tex]

### Comparison of limits:
For the function to be continuous at [tex]\( x = -2 \)[/tex], the left-hand limit and the right-hand limit must be equal.

In this case:
[tex]\[ \lim_{{x \to -2^-}} f(x) = -1 \][/tex]
[tex]\[ \lim_{{x \to -2^+}} f(x) = -7 \][/tex]

Since [tex]\(-1 \neq -7\)[/tex], the function is not continuous at [tex]\( x = -2 \)[/tex].

### Conclusion:
Therefore, the function [tex]\( f(x) \)[/tex] has a discontinuity at [tex]\( x = -2 \)[/tex].