Notes 1 sept 2025

What to do with self study?

Tips

Why should you learn calculus

Something with rockets and faster code and understanding different scaling of algorithms.

How to compare two algoritms

Using limits! $$ \lim_{n\to \infty }{\frac{f}{g}} = 0 \to g\text{ grows faster} $$

P1 Real numbers and the real line

Math notation.
$\mathbb{N}$ natural numbers: 0, 1, 2, … (sometimes without 0)
$\mathbb{z}$ integer numbers: …,-2,-1,0,1,2,…
$\mathbb{Q}$ rational numbers (fractions): $\frac{p}{q}$ with p, q $\in$ $\mathbb{z}$

Decimal expantion

Rational numbers has a repeating pattern
$\frac{1}{2} = 0.50000\overline{0}$
$\frac{1}{3} = 0.3333\overline{3}$

Intervals

IntervalAlternative notation
$(0,1)$$ 0 < x < 1 $
$[0,1)$$0 \le x < 1$
$(0,1]$$0 < x \le 1$
$[1,\inf)$$1 \le x < \inf $

Symbols

$\cup$ union
$\cap$ intersection
$\in$ element of
$\vee$ or
$\wedge$ and