Types of Continuity and Discontinuity Math Example 4

Follow the full solution, then compare it with the other examples linked below.

Example 4

medium
Find the value of cc that makes h(x)={cx+1xโ‰ค2x2โˆ’1x>2h(x) = \begin{cases} cx + 1 & x \leq 2 \\ x^2 - 1 & x > 2 \end{cases} continuous at x=2x = 2.

Solution

  1. 1
    For continuity: left limit = right limit = function value.
  2. 2
    Right limit: limโกxโ†’2+(x2โˆ’1)=3\lim_{x\to 2^+}(x^2-1) = 3.
  3. 3
    Left limit and value: limโกxโ†’2โˆ’(cx+1)=2c+1\lim_{x\to2^-}(cx+1) = 2c+1.
  4. 4
    Set equal: 2c+1=3โ‡’c=12c+1 = 3 \Rightarrow c = 1.

Answer

c=1c = 1
At a boundary point, continuity requires both one-sided limits to match. Set the two expressions equal at x=2x=2 and solve for cc.

About Types of Continuity and Discontinuity

Continuity types classify how a function can fail to be continuous at a point. A removable discontinuity (hole) occurs when the limit exists but doesn't equal f(a). A jump discontinuity occurs when left and right limits differ. An infinite discontinuity occurs when the function approaches ยฑโˆž.

Learn more about Types of Continuity and Discontinuity โ†’

More Types of Continuity and Discontinuity Examples