arrow
arrow
arrow
​Compute ​​lim⁡x→4(x2−7x+12)x−4\lim _{x \rightarrow 4} \frac{\left(x^2-7 x+12\right)}{x-4}x→4lim​x−4(x2−7x+12)​​​
Question

Compute

limx4(x27x+12)x4\lim _{x \rightarrow 4} \frac{\left(x^2-7 x+12\right)}{x-4}​​

A.

0

B.

2

C.

1

D.

-1

Correct option is C

First, try substituting x=4 directly into the expression:4274+1244=1628+120=00This is an indeterminate form, so we need to simplify the expression further.Factor the NumeratorFactor the quadratic expression in the numerator:x27x+12=(x3)(x4)So, the limit becomes:limx4(x3)(x4)x4Simplify the ExpressionCancel the common factor (x4) in the numerator and denominator (valid since x4):limx4(x3)Evaluate the Simplified LimitNow, substitute x=4 into the simplified expression:43=1\begin{aligned}&\text{First, try substituting } x = 4 \text{ directly into the expression:} \\&\frac{4^2 - 7 \cdot 4 + 12}{4 - 4} = \frac{16 - 28 + 12}{0} = \frac{0}{0} \\&\text{This is an indeterminate form, so we need to simplify the expression further.} \\\\&\textbf{Factor the Numerator} \\&\text{Factor the quadratic expression in the numerator:} \\&x^2 - 7x + 12 = (x - 3)(x - 4) \\&\text{So, the limit becomes:} \\&\lim_{x \to 4} \frac{(x - 3)(x - 4)}{x - 4} \\\\&\textbf{Simplify the Expression} \\&\text{Cancel the common factor } (x - 4) \text{ in the numerator and denominator (valid since } x \ne 4\text{):} \\&\lim_{x \to 4} (x - 3) \\\\&\textbf{Evaluate the Simplified Limit} \\&\text{Now, substitute } x = 4 \text{ into the simplified expression:} \\&4 - 3 = 1\end{aligned}​​

test-prime-package

Access ‘AAI JE ATC’ Mock Tests with

  • 60000+ Mocks and Previous Year Papers
  • Unlimited Re-Attempts
  • Personalised Report Card
  • 500% Refund on Final Selection
  • Largest Community
students-icon
175k+ students have already unlocked exclusive benefits with Test Prime!
test-prime-package

Access ‘AAI JE ATC’ Mock Tests with

  • 60000+ Mocks and Previous Year Papers
  • Unlimited Re-Attempts
  • Personalised Report Card
  • 500% Refund on Final Selection
  • Largest Community
students-icon
175k+ students have already unlocked exclusive benefits with Test Prime!