Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

lim_(x rarr3)(x-3)/(2-sqrt(x+1))=

limx3x32x+1= \lim _{x \rightarrow 3} \frac{x-3}{2-\sqrt{x+1}}=

Full solution

Q. limx3x32x+1= \lim _{x \rightarrow 3} \frac{x-3}{2-\sqrt{x+1}}=
  1. Substitute xx with 33: Substitute the value of xx with 33 in the expression to check if the limit can be directly calculated.\newlinelimx3x32x+1=3323+1\lim_{x \to 3}\frac{x-3}{2-\sqrt{x+1}} = \frac{3-3}{2-\sqrt{3+1}}
  2. Simplify after substitution: Simplify the expression after substitution to see if it results in an indeterminate form.\newline(33)/(23+1)=0/(24)=0/0(3-3)/(2-\sqrt{3+1}) = 0/(2-\sqrt{4}) = 0/0\newlineSince we get 0/00/0, this is an indeterminate form, and we cannot directly calculate the limit.
  3. Apply L'Hôpital's Rule: Apply L'Hôpital's Rule because we have an indeterminate form of 0/00/0. This rule states that if the limit as xx approaches aa of f(x)/g(x)f(x)/g(x) is 0/00/0 or /\infty/\infty, then the limit is the same as the limit of the derivatives of the numerator and the denominator, provided that the limit of the derivatives exists.\newlinelimx3x32x+1=limx3d/dx(x3)d/dx(2x+1)\lim_{x \to 3}\frac{x-3}{2-\sqrt{x+1}} = \lim_{x \to 3}\frac{d/dx(x-3)}{d/dx(2-\sqrt{x+1})}
  4. Differentiate numerator and denominator: Differentiate the numerator and the denominator with respect to xx. The derivative of the numerator (x3)(x-3) with respect to xx is 11. The derivative of the denominator (2x+1)(2-\sqrt{x+1}) with respect to xx is 12x+1-\frac{1}{2\sqrt{x+1}}. So, limx3ddx(x3)ddx(2x+1)=limx3112x+1\lim_{x \to 3}\frac{\frac{d}{dx}(x-3)}{\frac{d}{dx}(2-\sqrt{x+1})} = \lim_{x \to 3}\frac{1}{-\frac{1}{2\sqrt{x+1}}}
  5. Simplify after differentiation: Simplify the expression after differentiation.\newlinelimx3112x+1=limx3(2x+1)\lim_{x \to 3}\frac{1}{-\frac{1}{2\sqrt{x+1}}} = \lim_{x \to 3}(-2\sqrt{x+1})
  6. Substitute xx with 33: Substitute xx with 33 in the simplified expression after applying L'Hôpital's Rule.\newlinelimx3(2x+1)=23+1=24=22=4\lim_{x \to 3}(-2\sqrt{x+1}) = -2\sqrt{3+1} = -2\sqrt{4} = -2\cdot 2 = -4

More problems from Multiply using the distributive property