MCQ
 What is the value $ \lim_{\text{x} \rightarrow 4}\frac{\text{x}^2-2\text{x}-8}{\text{x}-4}$ :
  • A
    0
  • B
    2
  • C
    8
  • D
    6

Answer

  1. 6

Solution:

The denominator becomes 0, as x approaches 4.

$ \lim_{\text{x} \rightarrow 4}\frac{\text{x}^2-2\text{x}-8}{\text{x}-4}$ Here, if we factorize the numerator we get

$ \lim_{\text{x} \rightarrow 4}\frac{(\text{x}-4) (\text{x}+2)}{\text{x}-4}$

We can now cancel out (x - 4) from both the numerator and denominator.

We get, $ \lim_{\text{x} \rightarrow 4}(\text{x}+2)=6$

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