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    How do you do these?

    Differentiate with respect to x:

    a) x^4

    b) x^7/2

    c) 6

    h) 17.8

    Is a= 4x^3
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    (a) is correct. Repeat the pattern. Constants have a rate of change of zero.
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    How will you do it for whole numbers though?

    Also is x^7/2: 3.5x^2.5?
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    general rule is x^n = nx^n-1
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    (Original post by Deep456)
    Furthermore do I need to put:

    dy/dx (x^4) = 4x^3
    No, technically what you want is  \frac{d}{dx} (x^4) = 4x^3 but at this level you can just write y = x^4, then dy/dx = 4x^3.
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    (Original post by Deep456)
    How will you do it for whole numbers though?

    Also is x^7/2: 3.5x^2.5?
    Yeah that is right, and I would recommend writing dy/dx each time yeah, so as not to get confused when using more numbers and differentials.
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    (Original post by benwellsday)
    No, technically what you want is  \frac{d}{dx} (x^4) = 4x^3 but at this level you can just write y = x^4, then dy/dx = 4x^3.
    Any help on doing whole numbers though?
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    (Original post by Deep456)
    Any help on doing whole numbers though?
    Differentiating whole numbers? Yes, they become 0, here's one way of thinking about it.

     8 = 8x^0
    so y = 8
     \frac{dy}{dx} = 0 \times 8 \times x^{-1} = 0

    But in general you just differentiate them to 0 straight away.
 
 
 
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