By failing to prepare, you are preparing to fail.
A2017-04-02T20:16:44+10:00

## A

##### Definition
abscissa the x value of a coordinate (x, y)
absolute maximum the highest point on a curve within the natural or given domain
absolute minimum the lowest point on a curve within the natural or given domain
absolute value the absolute value makes a negative number positive, leaving positive numbers or zero unchanged. The absolute value of -2, expressed as |-2| = 2. The ‘lines’ about the number are called modulus. |x| would be called absolute x
acceleration the rate of change of velocity over time. Acceleration, often expressed as , is the first derivative of the velocity function, or the second derivative of the displacement function
acute angle also known as sharp angle. Angle less than 90° in magnitude
acute triangle triangle with all three angles less than 90°
adjacent angles two angles which share a common vertex and side ∠a and ∠b are adjacent angles

algebra maths using letters or symbols (pronumerals) as well as numbers
algorithm  set of instructions to solve a problem. An example of a very simple algorithm: 2 + 3, the plus sign instructs us to add the two numbers, giving us an answer of 5
alpha α Greek letter for a, commonly used to indicate unknown angles
alternate angles  alternate angles in parallel lines are equal and form a “z” shape

altitude  perpendicular height
am time after midnight and before midday, the morning (anti-meridian)
amplitude the height between the centre of a periodic function and its maximum height. The amplitude of y = sin x and y = cos x is 1

analogue clock clock with hands that rotate around the face to show the time (opposite to digital clock)
angle the measurement of the size of ‘turn’ between two lines
angle of depression the angle from the horizontal looking down

angle of elevation the angle from the horizontal looking up

angle sum of polygon angle sum of any polygon = (n – 2) x 180°, where n is the number of sides in the polygon
annual per year
annulus the area between concentric circles. The formula to find the annulus is

A = π(R2 – r2)  or A = πR2 – πr2

annum year
anticlockwise opposite direction a clock moves. Anticlockwise would be a circular movement to the left, rather than the right
antiderivative the primitive or integral of a function
apex the top of a shape, the highest point
approximate to estimate or guess the number, not do exact calculations
arc the part of a circle’s circumference

arc length ℓ= πr
area the region bounded inside a shape
arithmetic progression a sequence of numbers that have a common difference.

eg: 1, 5, 9, 13…. all have a difference of 4
arithmetic series a sequence of numbers with a common difference that are being added.

eg: 1 + 5 + 9 + 13 + ….
ascending going up, ascending order means going from smallest to largest.
asymptote a number or a line that is never quite reached. A curve is said to be asymptotic if it approaches a value, but never actually touches it.
average or mean, expressed often as . To calculate the average of a set of numbers, add up all of the numbers and then divide by how many numbers there are. example: the average of 1, 2 ,4, 5 and 8 would be $\frac{1 + 2 + 4 + 5 + 8}{5}=\frac{20}{5}$= 4
axis of symmetry the line dividing a shape or function exactly in half so that it is the same on both sides, a mirror image
axis of symmetry of a parabola $x=-\frac{b}{2a}$