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Find the limit as x approaches 4 of (x - 4) / (√x - 2).

A) 1/4
B) 1/2
C) 4
D) 8

User Xeraphim
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1 Answer

2 votes

Final answer:

To find the limit of (x - 4) / (√x - 2) as x approaches 4, multiply the expression by its conjugate to cancel out the (x - 4) term, which ultimately results in the answer being 4. Option c is the correct answer.

Step-by-step explanation:

The student has asked to find the limit as x approaches 4 of the expression (x - 4) / (√x - 2). To solve the mathematical problem completely, we need to address the fact that if we directly substitute x = 4 into the expression, we would get a 0/0 form which is undefined. This suggests that there is a common factor in the numerator and the denominator that we need to eliminate.

Let's factor by multiplying the numerator and the denominator by the conjugate of the denominator:

  • Multiply by (√x + 2) / (√x + 2)
  • This gives: ((x - 4)(√x + 2)) / ((√x - 2)(√x + 2))
  • Simplify to get (x - 4) * (√x + 2) / (x - 4)
  • Cancel out the (x - 4) terms.
  • Now we have (√x+ 2)

We then directly substitute x = 4 and find the limit is 2 + 2, which is 4. Hence, the mention correct option answer in the final answer to the limit as x approaches 4 of (x - 4) / (√x - 2) is option C) 4.

User Oceans
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