1. Definitions
For any real numbers $a$, $b$, $c$ and $d$. Let $z=a+bi$, whe… Read
Revision Note - Math - Number and Algebra
Arithmetic Sequences
Let $T(1)$, $T(2)$, …, $T(n)$ be an arithmetic seque… Read
Direct Variation
If $y \propto x$ (i.e. $y$ varies directly as $x$), then we ha… Read
Discriminant
For quadratic equation $ax^2+bx+c=0$, where $a$, $b$ and $… Read
Division Algorithm
When $f(x)$ is divided by $d(x)$, if the quotient is $Q(x)$ a… Read
Estimations
- Round up
- $12345 \approx 12350$ (rounding up to 4 sig. fig.)
- $
Factor Theorem
- If $f(x)$ is divisible by $(x-a)$, where $a$ is a real number
Fibonacci Sequence
The sequence of numbers $1$, $1$, $2$, $3$, $5$, $8$, $13$, $… Read
Geometric Sequences
Let $T(1)$, $T(2)$, …, $T(n)$ be an geometric sequen… Read
Growth and Decay
Denote $O$ and $N$ the old value and new value respectively, … Read
Index of Earthquakes – the Richter Scale
The relation between the magnitude ($M$) of an earthquake a… Read
Inverse Variation
If $y \propto \frac{1}{x}$ (i.e. $y$ varies inversely as $x… Read
Joint Variation
If $y$ varies directly as $x$ and inversely as $z$, then we ha… Read
Laws of Indices
For any real numbers $a$, $b$ and $c$, any rational numbers $… Read