Equations

**Difference of squares**

(a+b)(a-b) = a2 - b2

**Identities and Equations**

2x+x=3x is an identity because it is true for all values of x

2x+1=3 is an equation because it is only true for x=1

If an equation contains **fractions**,then you **cross-multiply** to remove the brackets.

FOLI:

In IGCSE Mathematics curriculum, if there are three brackets, multiply out the **first two brackets** then multiply by the remaining bracket

Graphs

**Quadratic graphs**have**x2**as the**highest power**in IGCSE Mathematics.

- A quadratic graph is called a
**parabola** - A parabola has a
**vertical line of symmetry**and is**infinite** **Cubic graphs**have**x3**as the highest power and will look similar to this

Gradient

The equation of a straight line is **y=mx+c** where m is the gradient and c is the y intercept

If the gradient of a straight line is m,the gradient of the line **perpendicular** to m is **-1/m**

Standard index form

In IGCSE Mathematics currciculum, **standard index** form can be used to express **very large or very small quantities**

For example:

- 524 = 5.24x102
- 0.0467 = 4.67x10-2

End of this topic!

Drafted by Gina (Mathematics)