Definition of equation in English:



  • 1Mathematics
    A statement that the values of two mathematical expressions are equal (indicated by the sign =).

    • ‘The first person known to have solved cubic equations algebraically was del Ferro but he told nobody of his achievement.’
    • ‘When I pressed him to write an equation expressing the value for a, he insisted that he would need a symbol for within.’
    • ‘The movement associated with each mode can be expressed by the motion equation for a single degree-of-freedom system.’
    • ‘An encryption algorithm is a mathematical equation containing the message being encrypted or decrypted.’
    • ‘These laws are very precise and can be expressed by exact mathematical equations.’
    • ‘Lagrange's main object was to find out why cubic and quartic equations could be solved algebraically.’
    • ‘He replaced the differential operator d/dx by a variable p transforming a differential equation into an algebraic equation.’
    • ‘It also contains continued fractions, quadratic equations, sums of power series and a table of sines.’
    • ‘The sections on equations cover quadratic equations where he discusses two solutions.’
    • ‘Now express the pattern as a mathematical equation.’
    mathematical problem, sum, calculation, question
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  • 2mass noun The process of equating one thing with another.

    ‘the equation of science with objectivity’
    • ‘The facts reduce themselves to a terrible equation of time and consequence.’
    • ‘I feel that I have developed some sort of equation with them.’
    • ‘One-half of the general problem of stellar atmospheres revolves around the solution of the equation of radiative transfer.’
    • ‘And can you tell us, are you concerned about second-guessing on that whole equation?’
    • ‘The simple equation of balancing caloric intake and exercise is the key to fitness.’
    • ‘As relationships go, I realized this simple equation of life.’
    • ‘I say two, because another managerial solution to this quandary is to work on the slightly simpler equation of four into three.’
    equating, equalization, identification, association, connection, likening, matching
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    1. 2.1the equation A situation in which several factors must be taken into account.
      ‘money also came into the equation’
      • ‘Yet rising U.S. interest rates and a still-strong dollar must be factored into that equation.’
      • ‘Another factor in the equation: Used equipment must compete with new equipment in the marketplace.’
      • ‘Food/energy balance is the simple equation of calories in/calories out.’
      • ‘So let me analyse the business element of that equation.’
      • ‘Even the simplest of pots was a chore and ‘position’ did not even enter into the equation.’
      • ‘In these and other ways, care theorists distance themselves from any simple equation of subjective hurt and moral claims.’
      • ‘The current price of oil, states the release, is a critical ingredient in the tourism industry and must be factored into the equation.’
      • ‘The second part of that equation seems to have been abandoned by feminists early on.’
      • ‘It was a simple and compelling equation: the bigger the wave the better your bottom-line.’
      • ‘So the children issue doesn't really enter into the equation.’
      • ‘This deprivation of culture, of identity, is the missing link in Africa's development equation.’
      • ‘The fact that he might have to do without doesn't enter into the equation for some in the animal protection industry.’
      • ‘It doesn't enter into the equation, because it's not part of the culture.’
      • ‘And the small matter of lost tax revenue doesn't enter into the equation at all, of course.’
      • ‘Concern for life just does not belong in the profit/loss equation.’
      • ‘Once all that is figured out, the most confusing factor in the equation must be pondered: playing time.’
      • ‘When pressure of competition was factored into the equation, the situation changed.’
      • ‘We have explained the process of the enabling development equation.’
      • ‘The perception of our success up to this point will be a critical part of that equation.’
      • ‘Even on stark issues like abortion, there can be no simple equation between the church and any political program or party.’
      the situation, the problem, the case, the question, the quandary, the predicament
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  • 3Chemistry
    A symbolic representation of the changes which occur in a chemical reaction, expressed in terms of the formulae of the molecules or other species involved.

    • ‘I asked as I balanced a chemical equation and answered some questions.’
    • ‘When hydrolysis occurs, we will write a chemical equation to describe it, and new species will be formed in solution.’
    • ‘The final system is the aerobic system. aerobic meaning it requires oxygen as part of its chemical equation to function.’
    • ‘The isotopic data do not conform to a simple mixing equation.’
    • ‘The chemical equations for some reactions may have a lone reactant or a single product.’


  • equation of the first (or second etc.) order

    • An equation involving only the first derivative, second derivative, etc.

      • ‘His doctoral dissertation was on the theory of the propeller which led to his developing a theory of partial differential equations of the second order.’
      • ‘Special attention should be drawn also to his little known pamphlet on regular point of linear differential equations of the second order used for a number of years in connection with one of his courses of lectures.’
      • ‘He began mathematical research while still an undergraduate and his first paper, On the isoclinal lines of a differential equation of the first order was published in the Proceedings of The Royal Society of Edinburgh in 1903.’
      • ‘This integral was introduced in a paper on differential equations of the second order which he wrote in 1870.’
      • ‘He did this by using an indeterminate equation of the second order, Nx 2 + 1 = y 2, where N is the number whose square root is to be calculated.’


Late Middle English: from Latin aequatio(n-), from aequare ‘make equal’ (see equate).