$$ \text{Chapter 1: Quadratic} $$

Quadratic equation: $ax^2+bx+c=0$:

• A parabola with vertex at the stationary point
• Stationary point(minimum & maximum point), turning point, have gradient $m=0$
• Sketch graph:

Solve quadratics equations:

• Factorisation:

• Complete the square:

• Discriminant: $b^2-4ac$

Intersection with a line:

• Find $x$ from $f(x)=g(x)$

Or

• Substitute $x$ from 1 side to the other
• Discriminant: $b^2-4ac$

$$ \text{Chapter 2: Functions} $$

Functions: $y=f(x)$

• Take input within a domain $x$ and output $y$ within a range
• One-one functions: 1 value of $x$ for 1 value of $y$
• Many-one functions: more than $x \text{ or }y$ can results to the other, ex: $x^2,\sqrt{x}$

Composite functions: $\displaystyle f(g(x))$