I have a problem which arises whenever I look at the derivate as an operator on a function:(adsbygoogle = window.adsbygoogle || []).push({});

when x and t both represent a (different) unknown value from the same set X, the output need not be the same:

y = f(x)

z = f(t)

When calculating the derivatives for these 2:

dy/dx = d(f(x))/dx = Df(x) = df/dx (x) = df/dt (x)

dz/dt = d(f(t))/dt = Df(t) = df/dt (t) = df/dx (t)

Example:

if f represents the cosine function, it doesn't matter whether I differentiate cos(x) to x or cos(t) to t and then evaluate the result at an unknown point x or t, depending on what I need. So here's my question...does it actually matter to which variable I differentiate this?

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# Question about derivatives

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