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lim_(x rarr-4)(x+4)/(sqrt(3x+13)-1)=

limx4x+43x+131= \lim _{x \rightarrow-4} \frac{x+4}{\sqrt{3 x+13}-1}=

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Q. limx4x+43x+131= \lim _{x \rightarrow-4} \frac{x+4}{\sqrt{3 x+13}-1}=
  1. Identify Function & Point: Identify the function and the point at which we need to find the limit.\newlineWe have the function f(x)=x+43x+131f(x) = \frac{x+4}{\sqrt{3x+13}-1} and we need to find the limit as xx approaches 4-4.
  2. Substitute x=4x = -4: Substitute x=4x = -4 into the function to see if the limit can be directly calculated.limx4x+43x+131=4+43(4)+131=012+131=00\lim_{x \to -4} \frac{x+4}{\sqrt{3x+13}-1} = \frac{-4+4}{\sqrt{3(-4)+13}-1} = \frac{0}{\sqrt{-12+13}-1} = \frac{0}{0}We encounter an indeterminate form 0/00/0, which means we cannot directly calculate the limit.
  3. Apply Algebraic Manipulation: Apply algebraic manipulation to eliminate the indeterminate form. We can multiply the numerator and the denominator by the conjugate of the denominator to rationalize it. The conjugate of 3x+131\sqrt{3x+13}-1 is 3x+13+1\sqrt{3x+13}+1.
  4. Multiply by Conjugate: Multiply the function by the conjugate over itself.\newlinelimx4(x+4)(3x+13+1)(3x+131)(3x+13+1)\lim_{x \to -4} \frac{(x+4)(\sqrt{3x+13}+1)}{(\sqrt{3x+13}-1)(\sqrt{3x+13}+1)}
  5. Apply Difference of Squares: Apply the difference of squares formula to the denominator.\newlineThe difference of squares formula is (ab)(a+b)=a2b2(a-b)(a+b) = a^2 - b^2.\newlinelimx4(x+4)(3x+13+1)(3x+13)(1)2\lim_{x \to -4} \frac{(x+4)(\sqrt{3x+13}+1)}{(3x+13) - (1)^2}
  6. Simplify Denominator: Simplify the denominator.\newlinelimx4(x+4)(3x+13+1)3x+131\lim_{x \to -4} \frac{(x+4)(\sqrt{3x+13}+1)}{3x+13 - 1}\newlinelimx4(x+4)(3x+13+1)3x+12\lim_{x \to -4} \frac{(x+4)(\sqrt{3x+13}+1)}{3x+12}
  7. Cancel Common Factors: Cancel out the common factor of (x+4)(x+4) in the numerator and the factor of 3(x+4)3(x+4) in the denominator.\newlinelimx43x+13+13\lim_{x \to -4} \frac{\sqrt{3x+13}+1}{3}
  8. Substitute x=4x = -4: Substitute x=4x = -4 into the simplified function to find the limit.limx4[3(4)+13+1]/3=[12+13+1]/3=[1+1]/3=(1+1)/3=23\lim_{x \to -4} \left[\sqrt{3(-4)+13}+1\right] / 3 = \left[\sqrt{-12+13}+1\right] / 3 = \left[\sqrt{1}+1\right] / 3 = (1+1) / 3 = \frac{2}{3}

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