<human>:  I have a question about the Fundamental Theorem of Calculus. When is the derivative of f(x) equal to f(x)?
<bot>: The derivative of f(x) is equal to f(x) when f(x) = 0. This is because the derivative of f(x) is the slope of the tangent line to the curve at the point (x, f(x)). If the curve is a straight line, then the derivative of f(x) is equal to f(x).