Identify Limit: Identify the limit to be calculated.We need to find the limit of the function (x3−9x)/(x2−3x) as x approaches 3.
Direct Substitution: Direct substitution to check for indeterminate forms.Substitute x=3 into the function to see if the limit can be calculated directly.limx→3x2−3xx3−9x=32−3⋅333−9⋅3=9−927−27=00We have an indeterminate form, so we cannot calculate the limit by direct substitution.
Factor Expression: Factor the numerator and denominator to simplify the expression.Factor out the common terms in the numerator and the denominator.Numerator: x3−9x=x(x2−9)=x(x+3)(x−3)Denominator: x2−3x=x(x−3)
Cancel Common Factors: Cancel out the common factors.The term (x−3) is common in both the numerator and the denominator and can be canceled out.limx→3x(x−3)x(x+3)(x−3)=limx→3(x+3)
Calculate Simplified Limit: Calculate the limit of the simplified expression.Now that the expression is simplified, we can substitute x=3 directly.limx→3(x+3)=3+3=6
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