f'(c) the derivative of the function f evaluated at x=c can be interpreted as The slope of a secant line to the graph of the function f(x) passing trough the point (c, f(c)). The slope of the tangent line to the graph of the function f(x) at a point where the function f(x) has a rela maximum. The slope of the tangent line to the graph of f(x) at the origin. The slope of the tangent line to the graph of the function f(x) at the point (c,f(c))