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Math Help - Differentiate using product Rule

  1. #1
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    Differentiate using product Rule

    Is This correct?

    (x+20)^4 (x-30)^3

    u=(x+20)^4

    du/dx = 4(x+20)^3

    v=(x-30)^3

    dv/dx=3(x-30)^2

    dy/dx=v.du/dx + u . dv/dx

    dy/dx = (x-30)^3 . 4 (x+20)^3 + (x+20)^4 . 3(x-30)^2
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  2. #2
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    yes

    ( f( x )*g( x ) ) ' = f ' ( x )*g( x ) + g ' ( x )*f( x )

    you can put:

    if f( x ) = ( x + 20 )^4 => f ' ( x ) = 4*( x + 20 )^3

    g( x ) = ( x - 30 )^3 => g ' ( x ) = 3*( x - 30 )^2

    and if I use that in the formula above i will get the same thing as you
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  3. #3
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    Quote Originally Posted by Maths_noob View Post
    Is This correct?

    (x+20)^4 (x-30)^3

    u=(x+20)^4

    du/dx = 4(x+20)^3

    v=(x-30)^3

    dv/dx=3(x-30)^2

    dy/dx=v.du/dx + u . dv/dx

    dy/dx = (x-30)^3 . 4 (x+20)^3 + (x+20)^4 . 3(x-30)^2
    Looks right to me
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  4. #4
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    Nectar thats lovely jubbly then
    Finaly! I know how to use the product rule
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