Q. Let g(x)=x−4−1x−5 when x=5.g is continuous for all x>4.Find g(5).Choose 1 answer:(A) 5(B) 10(C) 2(D) 8
Given function: We are given the function g(x)=x−4−1x−5 and we need to find the value of g(5). Direct substitution of x=5 into the function would result in a 00 indeterminate form, so we need to manipulate the function to remove the discontinuity at x=5.
Rationalizing the denominator: To remove the discontinuity, we can rationalize the denominator by multiplying the numerator and the denominator by the conjugate of the denominator. The conjugate of x−4−1 is x−4+1.
Simplifying the expression: Multiply the numerator and denominator by the conjugate to simplify the expression:g(x) = (x−4−1)⋅(x−4+1)(x−5)⋅(x−4+1).
Further simplifying the denominator: Simplify the denominator using the difference of squares formula (a−b)(a+b)=a2−b2:g(x) = (x−4)−1(x−5)∗(x−4+1).
Cancellation of terms: Further simplify the denominator:g(x)=x−5(x−5)⋅(x−4+1).
Substituting x=5: Now, we can cancel out the (x−5) term in the numerator and the denominator, as long as x is not equal to 5. However, since we are interested in the limit as x approaches 5, this cancellation is valid for the purpose of finding g(5):g(x)=x−4+1.
Calculating the result: Substitute x=5 into the simplified expression to find g(5):g(5)=5−4+1.
Calculating the result: Substitute x=5 into the simplified expression to find g(5): g(5)=5−4+1.Calculate the square root and the sum: g(5)=1+1=1+1=2.