Define the term inverse proportionality? Then differentiate between direct and Inverse proportionality. ?

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  • 3 months ago

    A dependent variable is inversely proportional when its value increases linearly with a decreasing value of the independent variable or decreases linearly with an increasing value of the independent variable.

    A dependent variable is directly proportional when its value increases linearly with an increasing value of the independent variable or decreases linearly with a decreasing value of the independent variable.

    EX:  When y = k/x it is inversely proportional to x as when x gets smaller y gets bigger and vice versa.  But when y = kx it is directly proportional to x as when x gets smaller y gets smaller and vice versa.

  • 3 months ago

    It's pretty simple.

    If two terms are directly proportional, then as one goes up, the other also goes up by some constant factor.

    A common example is wages. If you are paid $10 an hour, then as you work more hours, your wage goes up. Wages and hours are *directly* proportional.

    If two terms are inversely proportional, then as one goes up, the other goes down.

    A common example is speed and time. For example, if you drive to work (30 miles away) at a slower speed it takes *more* time. But if you drive to work at a faster speed, it takes *less* time. Speed and time are *inversely* proportional

    In the first case, you can model that as a constant *times* the second variable.

    Wages = Fixed hourly rate * hours

    w = 10 * h

    In the second case, you can model that as a constant *divided* by the second variable.

    Time = Fixed distance / Speed

    t = 30 / s

    In general, if we say y is *directly* proportional to x, you'd write:

    y = kx

    If you say y is *inversely* proportional to x, you'd write:

    y = k/x

    In both cases, k is the constant of proportionality. The only difference is you multiply by x in the direct case and you divide by x in the inverse case.

  • Anonymous
    3 months ago

    Is there any reason you don't award a Best Answer?  E.g. https://au.answers.yahoo.com/question/index?qid=20...

  • ?
    Lv 7
    3 months ago

    Given 2 variables x and y, x has INVERSE PROPORTIONALITY to y if

    .................1

    ..........y = --- x

    .................k

    where k is some constant.

    Similarly, x has DIRECT PROPORTIONALITY to y if

    ..........y = k x

    where k is some constant.

    Example of DIRECT PROPORTIONALITY: The more money you have, the more food you can buy.

    Example of INVERSE PROPORTIONALITY. The more money you spend, the less savings you have.

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