MATH 2301-100 Spring 2022 Calculus I Recitation 2 Week 2

Work in a group of at most 4. Explain to those who do not understand. Ask questions if you do not understand.

  1. (20 points) Describe three situations where \(\displaystyle \lim_{x\rightarrow c} f(x)\) does not exist.
  2. (25 points) A machinist is required to manufacture a circular metal disk with area \(1000\, \mathrm{cm}^2\).
    1. What radius produces such a disc?
    2. If the machinist is allowed an error tolerance of \(\pm 3\, \mathrm{cm}^2\) in the area of the disk, how close to the ideal radius you found above must the machinist control the radius?
    3. In terms of the \(\epsilon\), \(\delta\) definition of \(\displaystyle \lim_{x\rightarrow a} f(x)=L\), what is \(x\)? What is \(a\)? What is \(L\)? What value of \(\epsilon\) is given? What is the corresponding value of \(\delta\)?
  3. (25 points)
    1. Define "\(\displaystyle \lim_{x\rightarrow c} f(x) =L\)".
    2. Using the definition, prove that \(\displaystyle \lim_{x\rightarrow 3} 5 x^2 = 45\).
  4. (30 points) Simplify and cancel so that you can plug in the given value without dividing by 0. Then plug in the value.
    1. For \(x=2\), \( \frac{x^2+x-6}{x-2}=\)
    2. For \(x=4\), \( \frac{\sqrt{x}-2}{x-4}=\)
    3. For \(h=0\), \( \frac{(x+h)^2 -x^2}{h}=\)
    4. For \(h=0\), \( \frac{(x+h)^{-1} - x^{-1}}{h}=\)
    5. For \(h=0\) and \(f(x)=2x^2\), \(\frac{f(x+h) -f(x)}{h}=\)

Last modified: Sun Jan 2 20:07:14 UTC 2022