Identify Indeterminate Form: Identify the indeterminate form.We need to evaluate the limit of the function as x approaches 12. Let's first plug in the value of x into the function to see if it results in an indeterminate form.limx→12(x+4−4)/(x−12)=(12+4−4)/(12−12)=(16−4)/0=(4−4)/0=0/0This is an indeterminate form, so we cannot directly calculate the limit by substitution.
Algebraic Manipulation: Apply algebraic manipulation to simplify the expression.To resolve the indeterminate form, we can multiply the numerator and the denominator by the conjugate of the numerator. The conjugate of x+4−4 is x+4+4.limx→12(x−12x+4−4)⋅(x+4+4x+4+4)=limx→12((x−12)(x+4+4)x+4−16)
Simplify Expression: Simplify the expression further.Now, we simplify the numerator and the denominator.limx→12((x−12)(x+4+4)x+4−16)=limx→12((x−12)(x+4+4)x−12)We can see that (x−12) in the numerator and denominator will cancel out, as long as x=12.limx→12(x+4+41)
Evaluate Limit: Evaluate the limit of the simplified expression.Now that we have simplified the expression, we can substitute x=12 directly into the remaining expression.limx→12(x+4+41)=12+4+41=16+41=4+41=81