There is no particular symbol for "no change". However, if you know the quantity that has not changed, for example represented by H, you could write "ΔH = 0". Δ is the accepted symbol for "change in/of .." so if the change equals zero then there is no change.
A linear equation contains only the first power of the unknown quantity. Thus, 5x - 3 = 7 and x/6 = 4 are both linear equations. Linear equations have only one solution which is the value of the unknown that when substituted in the equation , makes the left hand side equal to the right hand side.Linear functions have the same limitation in terms of only containing the first power of the unknown quantity. They yield graphs that are straight lines and thus the name 'linear' is used. A simple linear function is f:x →2x + 1. This can also be written as f(x) = 2x + 1 or another identifying letter used such as y = 2x + 1. Consequently, for different values of the unknown quantity (in this case 'x') then the function also yields a different value.
Quantity refers to an amount, value, 'how many', how much'
The symbol is three vertical lines next to each other the symbol above is the symbol for approximately equal to.Wrong, the correct symbol is ~
Yes.
Variable
In maths the symbols x and n are usually used to represent an unknown quantity. These may be referred to as a variable.
x or any other variable
It is a variable and is expressed as a letter as for example it could be x or y
Nobody 'invented' it... letters are often used in maths to signify an unknown quantity.
x= the unknown
X is the symbol for multiplication, as in 2X2=4 X (or any other letter) is often used to represent an unknown quantity.
The Unknown Quantity - 1919 was released on: USA: 14 April 1919
An algebraic expression uses a letter to represent an unknown quantity.
A comparison between an unknown quantity and a standard is known formally as a measurement. In essence, by taking a measurement of a standard against an unknown quantity, you are creating your own system of measurement.
It is calibrating.
A variable is usually assumed to represent an unknown quantity. You don't need to "do" anything special to your variable.