D-2 More about Solving If f(x) has one or more local minima or minima, each occurs singly betweenadjacent roots of f(x) (figure d, below).In most situations, the calculated root is an accurate estimate of the theoretical,infinitely precise root of the equation. An "ideal" solution is one for which f(x) = 0.However, a very small non–zero value for f(x) is often acceptable because it mightresult from approximating numbers with limited (12–digit) precision.f (x)xaf (x)bxf (x)xcf (x)xdFunction Whose Roots Can Be Found