Derivative Notation

Discussion in 'Calculus' started by nycmathguy, Jun 2, 2022.

  1. nycmathguy

    nycmathguy

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    Derivative Notation

    The derivative of y is y'. Yes? Thus means y prime. Yes?

    The derivative of f(x) = f'(x). Yes? This means f prime of y. Yes?

    What about dy/dx? Does this mean the derivative of y with respect to x?

    What does d/dx mean?

    Can dy/dx be expressed as df(x)/dx?

    Any other way to represent the derivative?
     
    nycmathguy, Jun 2, 2022
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  2. nycmathguy

    MathLover1

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    Yes. y'(x) means y prime of x. Prime means the derivative.
    dx/dy also means the derivative.
    It's just different ways of writing same thing.
    dy/dx = df(x)/dx.......remember that f(x)=y
     
    MathLover1, Jun 2, 2022
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  3. nycmathguy

    nycmathguy

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    I like dy/dx, y prime and f prime of x.
    What d/dx mean?
     
    nycmathguy, Jun 2, 2022
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  4. nycmathguy

    MathLover1

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    d/dx is differentiating something that isn't necessarily an equation denoted by y.
    dy/dx
    is differentiating an equation y with respect to x
    dy/dx
    is a noun. It is the thing you get after taking the derivative of y.
    d/dx is a verb. It says "take the derivative of this thing I'm about to write after this"
     
    MathLover1, Jun 2, 2022
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  5. nycmathguy

    nycmathguy

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    My example:

    Find derivative of 2x^2 + 5x.

    d/dx [2x^2] + d/dx [5x]

    Answer: 4x + 5 is the slope.

    Can you give me an example using dy/dx?
     
    nycmathguy, Jun 3, 2022
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  6. nycmathguy

    MathLover1

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    Answer: 4x + 5 is the tangent line which has a slope=4

    y=2x^2 + 5x->using dy/dx
     
    MathLover1, Jun 3, 2022
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  7. nycmathguy

    nycmathguy

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    So, using dy/dx, we dy/dx = 4x + 5.

    Another example.

    Find derivative of y.

    So, d/dx [y] = dy/dx = y prime.
     
    nycmathguy, Jun 3, 2022
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  8. nycmathguy

    MathLover1

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    yes

    We denote derivative by dy/dx, the change in y with respect to x.

    If y(x) is a function, the derivative is represented as y’(x)
    dy/dx=y’(x)
     
    MathLover1, Jun 3, 2022
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  9. nycmathguy

    nycmathguy

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    What would be dx/dy?
     
    nycmathguy, Jun 3, 2022
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  10. nycmathguy

    MathLover1

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    What would be dx/dy?

    upload_2022-6-2_19-39-35.gif
     
    MathLover1, Jun 3, 2022
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  11. nycmathguy

    nycmathguy

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    Are you say that the derivative of x is d/dy [x], which is dx/dy?

    I always thought that the derivative any variable is 1.
    No?

    Derivative of x = 1.

    Derivative of y = 1.

    Derivative of z = 1.

    No?
     
    nycmathguy, Jun 3, 2022
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  12. nycmathguy

    MathLover1

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    dx/dy is just derivative of inverse function
    if function is y(x) inverse is x(y)
     
    MathLover1, Jun 3, 2022
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  13. nycmathguy

    nycmathguy

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    Ok.
     
    nycmathguy, Jun 3, 2022
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