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lim_(x rarr3)(x^(3)-9x)/(x^(2)-3x)=

limx3x39xx23x= \lim _{x \rightarrow 3} \frac{x^{3}-9 x}{x^{2}-3 x}=

Full solution

Q. limx3x39xx23x= \lim _{x \rightarrow 3} \frac{x^{3}-9 x}{x^{2}-3 x}=
  1. Identify Limit: Identify the limit to be calculated.\newlineWe need to find the limit of the function (x39x)/(x23x)(x^3 - 9x) / (x^2 - 3x) as xx approaches 33.
  2. Direct Substitution: Direct substitution to check for indeterminate forms.\newlineSubstitute x=3x = 3 into the function to see if the limit can be calculated directly.\newlinelimx3x39xx23x=33933233\lim_{x \to 3}\frac{x^3 - 9x}{x^2 - 3x} = \frac{3^3 - 9\cdot 3}{3^2 - 3\cdot 3}\newline=272799= \frac{27 - 27}{9 - 9}\newline=00= \frac{0}{0}\newlineWe have an indeterminate form, so we cannot calculate the limit by direct substitution.
  3. Factor Expression: Factor the numerator and denominator to simplify the expression.\newlineFactor out the common terms in the numerator and the denominator.\newlineNumerator: x39x=x(x29)=x(x+3)(x3)x^3 - 9x = x(x^2 - 9) = x(x + 3)(x - 3)\newlineDenominator: x23x=x(x3)x^2 - 3x = x(x - 3)
  4. Cancel Common Factors: Cancel out the common factors.\newlineThe term (x3)(x - 3) is common in both the numerator and the denominator and can be canceled out.\newlinelimx3x(x+3)(x3)x(x3)=limx3(x+3)\lim_{x \to 3}\frac{x(x + 3)(x - 3)}{x(x - 3)} = \lim_{x \to 3}(x + 3)
  5. Calculate Simplified Limit: Calculate the limit of the simplified expression.\newlineNow that the expression is simplified, we can substitute x=3x = 3 directly.\newlinelimx3(x+3)=3+3=6\lim_{x \to 3}(x + 3) = 3 + 3 = 6

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