The question is to find the nth derivative of:(adsbygoogle = window.adsbygoogle || []).push({});

[tex]

f(x) = (ax - b)^-1

[/tex]

the answer in the book is:

[tex]

f^[n](x) = n!(-a)^n(ax-b)^{-1-n}

[/tex]

now I know that the nth derivative of:

[tex]

f(x) = x^-1

[/tex]

is:

[tex]

(-1)^nn!x^{-1-n}

[/tex]

but why would the nth of ax be a^n? Shouldn't it be 0 for every n over 1 which would make the whole term 0?

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# Nth derivative 2

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