In mathematics and science, a formula is a rule or statement written in algebraic symbols. The plural of formula can be written in two ways: formulae or formulas - the choice is based on personal preference.
Formulas use letters instead of words. A simple example of a formula is y = x. If x=1, the formula y=x would make the statement that x is the same thing as y, therefore, y=1.
In mathematics, a formula can also be an identity which equates two mathematical expressions together. Some key formulas under this category include the Pythagorean theorem, binomial theorem, Euler's formula and De Moivre's formula.[1] The expression "V=lwh", which relates the volume V to the length l, width w and height h of a rectangular box, is another example of a formula in geometry.[2]
In science, one of the most well known formulas is the formula for energy, e = mc2, created by Albert Einstein. Here, e represents energy, m represents mass and c is the speed of light. Thus, energy = mass × speed of light 2.
The formula e = mc2 is also an equation. Every equation is a formula, but not every formula is an equation. For instance, the formula x≡y (x "is defined as" y) is not an equation, because no "=" sign is used.