Math Problem Statement

determine whether f is continuous at the given point F(x) = x^2+4/ x-2 when x+3

Solution

The function provided is f(x)=x2+4x2f(x) = \frac{x^2 + 4}{x - 2}, and we are tasked with determining whether it is continuous at x=3x = 3.

To check continuity at a given point, x=cx = c, the following conditions must be met:

  1. f(c)f(c) is defined.
  2. The limit limxcf(x)\lim_{x \to c} f(x) exists.
  3. The limit equals the function value: limxcf(x)=f(c)\lim_{x \to c} f(x) = f(c).

Step 1: Check if f(3)f(3) is defined

Substitute x=3x = 3 into the function: f(3)=32+432=9+41=131=13f(3) = \frac{3^2 + 4}{3 - 2} = \frac{9 + 4}{1} = \frac{13}{1} = 13 So, f(3)f(3) is defined and equals 13.

Step 2: Check if limx3f(x)\lim_{x \to 3} f(x) exists

To compute the limit, simply substitute x=3x = 3 into the expression: limx3f(x)=limx3x2+4x2=32+432=9+41=13\lim_{x \to 3} f(x) = \lim_{x \to 3} \frac{x^2 + 4}{x - 2} = \frac{3^2 + 4}{3 - 2} = \frac{9 + 4}{1} = 13 The limit exists and equals 13.

Step 3: Check if the limit equals f(3)f(3)

Since both the limit and the function value at x=3x = 3 are 13, the third condition for continuity is satisfied.

Conclusion:

The function f(x)f(x) is continuous at x=3x = 3.

Would you like more details or have any questions?

Here are 5 related questions:

  1. What happens if f(x)f(x) is evaluated at x=2x = 2?
  2. How do we handle discontinuities in rational functions?
  3. Can a function have a limit at a point but not be continuous at that point?
  4. What are different types of discontinuities?
  5. How can we determine if a piecewise function is continuous at a given point?

Tip: Always check for undefined points in rational functions, as they often cause discontinuities.

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Math Problem Analysis

Mathematical Concepts

Continuity
Limits
Rational Functions

Formulas

f(c) is defined: f(c)
Limit: lim(x → c) f(x)

Theorems

Continuity Theorem
Limit Theorem

Suitable Grade Level

Grades 10-12