Math Problem Statement

Determine the values of x for which the function f left parenthesis x right parenthesis equals StartRoot StartFraction 8 x Over x plus 1 EndFraction EndRoot is continuous. If the function is not​ continuous, determine the reason. Question content area bottom Part 1 Where is the function continuous or not​ continuous? A. The function is not continuous for all values of x less than or equal to 0 and greater than minus8. B. The function is not continuous for all values of x greater than 0 and less than 8. C. The function is not continuous for all values of x greater than 0 and less than 1. D. The function is continuous for all values of The function is continuous for all values of x between 0 and minus1. E. The function is continuous for all values of x between 0 and 8. F. The function is continuous for all values of x. G. The function is not continuous for all values of x less than 0 and greater than or equal to minus1.

Solution

The given function is:

f(x)=8xx+1f(x) = \sqrt{\frac{8x}{x + 1}}

To determine where this function is continuous, we need to check:

  1. Domain of the square root: The expression inside the square root must be non-negative. Therefore, we need:

8xx+10\frac{8x}{x + 1} \geq 0

  1. Denominator must not be zero: The denominator of the fraction x+1x + 1 should not be zero, so x1x \neq -1.

Step 1: Solve 8xx+10\frac{8x}{x + 1} \geq 0

We need to find the values of xx where the fraction is non-negative.

To do this, analyze the critical points of the expression:

  • The numerator, 8x8x, is zero at x=0x = 0.
  • The denominator, x+1x + 1, is zero at x=1x = -1.

Now, let's consider the sign of the fraction 8xx+1\frac{8x}{x + 1} in the following intervals:

  • Interval 1: x<1x < -1
  • Interval 2: 1<x<0-1 < x < 0
  • Interval 3: x>0x > 0

Sign analysis:

  • For x<1x < -1, both 8x8x and x+1x + 1 are negative, so the fraction is positive.
  • For 1<x<0-1 < x < 0, 8x8x is negative, and x+1x + 1 is positive, so the fraction is negative.
  • For x>0x > 0, both 8x8x and x+1x + 1 are positive, so the fraction is positive.

Thus, 8xx+10\frac{8x}{x + 1} \geq 0 holds in the intervals (,1)(0,)(-\infty, -1) \cup (0, \infty).

Step 2: Exclude points where the denominator is zero

We exclude x=1x = -1, as the denominator is zero there. Therefore, the function is undefined at x=1x = -1.

Step 3: Conclusion on Continuity

The function is continuous where the expression 8xx+10\frac{8x}{x + 1} \geq 0, except where the denominator is zero at x=1x = -1.

Thus, the function is continuous for x(,1)(0,)x \in (-\infty, -1) \cup (0, \infty).

Answer:

The function is continuous for all values of x except x=1x = -1.

Which option corresponds to this?

  • The answer is not explicitly listed, but based on the function's analysis, the function is continuous for all xx except x=1x = -1 (and it must be greater than or equal to 0 for the square root). However, the choice that best matches in spirit (even if not phrased exactly the same) would be G: "The function is not continuous for all values of x less than 0 and greater than or equal to -1."

Would you like me to clarify anything further or provide additional explanations?

Here are 5 follow-up questions:

  1. What would happen if the fraction inside the square root were negative?
  2. How does the continuity of rational functions generally depend on the domain of the function?
  3. Can you think of any real-world applications where this function might model something continuous?
  4. How would the solution change if the square root was removed?
  5. What role does the concept of limits play in determining continuity at specific points?

Tip: Always remember that functions involving square roots must have non-negative values under the root for real numbers to be considered valid.

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Math Problem Analysis

Mathematical Concepts

Continuity of Functions
Domain Restrictions
Square Root Functions
Rational Functions

Formulas

f(x) = sqrt(8x / (x + 1))
A function is continuous if it is defined and has no discontinuities in its domain.
The denominator of a rational function cannot be zero.

Theorems

Continuity Theorem
Domain Restrictions for Rational and Radical Functions

Suitable Grade Level

Grades 11-12, College Pre-Calculus