# Errata: The formula given for the rise time of a second order system in Table 6.1 is only approximate

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Location: page 195, line -3

The formula for rise time given in Table 6.1 is valid when rise time is defined as the "inverse of the largest slope in the step response", which is one possible definition of rise time, but this is not the definition used in the text. On p151, rise time is defined as "the time required for the signal to go from 10% to 90% of its final value". Hence the formula should only be used as an approximation.

(Contributed by C. W. Rowley, 26 Jan 2011)