The Babylonian mathematicians are the main cause for the origin of algebra several thousands years ago. The term algebra is it defines the numbers to be represented as variables . Algebra is classified into two categories;

They are,

  • Ancient algebra and

  •  Modern algebra.

     

Ancient algebra mainly deals with elementary level of solving problems which involves basic arithmetic operations only. Algebra mostly consists of letters and symbols. Each letter and symbol has certain meanings. In this article we are going to see about algebra letters and meanings.

Meaning of letters in Algebra:

The word algebra means the branch of math that deals with the numbers denoted as letters or alphabets of English alphabets.

For example a number in general can be represented by `n` . The most common value or letter used in algebra is `x` .The area is denoted by `A` , volume is denoted by `V` , length is denoted by `l` , width is denoted by `w` , height is denoted by `h` , radius is denoted by `r` , time is denoted as `t` or `T` , base of a 3 - dimensional object is `b` ,area of triangle is denoted by `Delta` ,side is denoted by `s` etc.

  

Meaning of algebra letters in table form:

 

 Here are some letters and their meanings in algebra:

Symbol

Symbol Name

Meaning/ definition

Example

x, y

x and y variable

unknown value to find

when 3x = 6, then x = 2

equivalence

identical to

x ≡ y

equal by definition

equal by definition

 x≜y

~

approximately equal

weak approximation

11 ~ 10

approximately equal

approximation

sin(0.01) ≈ 0.01

proportional to

proportional to

f(x) ∝ g(x)

lemniscates

infinity symbol

x<=

much less than

much less than

1 ≪ 1000000

much greater than

much greater than

1000000 ≫ 1

( )

parentheses

calculate expression inside first

3 * (4+6) = 30

[ ]

brackets

calculate expression inside first

[(1+2)*(1+5)] = 18

{ }

braces

set

{2,3,4,5}

x

floor brackets

rounds number to lower integer

⌊4.3⌋= 4

x

ceiling brackets

rounds number to upper integer

⌈4.3⌉= 5

x!

exclamation mark

factorial

3! = 1*2*3 = 6

f (x)

function of x

maps values of x to f(x)

f (x) = 3x+5

(a,b)

open interval

(a,b) ≜ {x | a < x < b}

x ∈ (2,6)

[a,b]

closed interval

[a,b] ≜ {x | axb}

x ∈ [2,6]

delta

change / difference

t = t1 - t0

discriminant

Δ = b2 - 4ac

 

sigma

summation - sum of all values in range of series

xi= x1+x2+...+xn

∑∑

sigma

double summation

 

capital pi

product - product of all values in range of series

xi=x1∙x2∙...∙xn

e

e constant / Euler's number

e = 2.718281828...

.e = lim (1+1/x)x , x→∞

 

 

Meaning of letters in algebra continued:

 

Symbol

Symbol Name

Meaning/ definition

Example

 +

Plus

Addition of numbers

2 + 3 = 5

 -

Minus

Subtraction of numbers

3 – 2 = 1

X

Product

Multiplication of numbers

5 x 4 = 20

/

Division

Divide the numbers

`10/2` = 5

 =

Equal

Equal to

2 = 2

Not equal to

The given equation is not equal

X + 5 ≠ x + 3

±

Plus or minus

Both positive and negative numbers

Sqrt 16 = ± 4

`alpha`

alpha

Alpha value

x <= `alpha`

`beta`

beta

Beta value

 y>= `beta`

`theta`

theta

Used to represent degree of angle

`theta` = 45 degree

`sigma`

sigma

Sigma value

`sigma =sum(fd^2)/N`

`_|_`

perpendicular

Perpendicular line

`angle A_|_angleB`