Q. Let g(x)=x−4−1x−5 when x=5. g
is continuous for all x>4.Find g(5).
Recognize Indeterminate Form: To find the value of g(5), we need to evaluate the limit of g(x) as x approaches 5, because the function is not defined at x=5 but is continuous for x > 4. We will use the limit process to find g(5).
Rationalize Denominator: First, we recognize that direct substitution of x=5 into g(x) results in an indeterminate form (0/0). To resolve this, we can multiply the numerator and the denominator by the conjugate of the denominator to rationalize it.
Multiply by Conjugate: The conjugate of the denominator x−4−1 is x−4+1. We multiply both the numerator and the denominator by this conjugate:g(x)=(x−4−1)(x−4+1)(x−5)(x−4+1).
Simplify Denominator: Simplifying the denominator using the difference of squares, we get: g(x)=(x−4)−1(x−5)(x−4+1).
Cancel Terms: Further simplifying the denominator, we have:g(x) = [$x−5x−4+1] / [x - 5]\).
Final Simplification: Now, we can see that the (x−5) terms in the numerator and denominator will cancel out, as long as x is not equal to 5. This cancellation is valid because we are considering the limit as x approaches 5, not the value at x=5.
Substitute x=5: After canceling out the (x−5) terms, we are left with:g(x) = x−4+1.
Calculate g(5): Now we can safely substitute x=5 into the simplified function to find the limit as x approaches 5:g(5)=5−4+1=1+1=1+1.
Calculate g(5): Now we can safely substitute x=5 into the simplified function to find the limit as x approaches 5:g(5)=5−4+1=1+1=1+1.Therefore, g(5)=2. This is the value of the function g(x) as x approaches 5.