mogoz

Calculus

tags
Math

The mathematics of change. 🌠

FAQ

Is dy/dx a function?

Limits

Basic idea: When \(x\) is approaching the some number, what is \(f(x)\)/\(y\)/the function approaching?

  • For \(f(x)=\frac{x-1}{x-1}; f(x)=1, x\ne1\) i.e there is a discontinuity.
  • \(\lim\limits_{x\to1}\frac{x-1}{x-1}=1\) means that \(f(x)\) is also approaching 1 as \(x\) is approaching 1.

Another example,

\(g(x)=\begin{cases} x^2,x\ne2\\ 1,x=2 \end{cases}\)

  • \(\lim\limits_{x\to2}g(x)=4\) means that \(g(x)\) is approaching 4 as \(x\) is approaching 2.
  • But we can see that as soon as \(x\) is 2, \(g(x)\) will be \(1\).

Source: Introduction to limits - Khan Academyexternal link