This calculus video tutorial provides a basic introduction into increasing and decreasing functions. This video explains how to use the first derivative and a sign chart to determine the intervals where the function is increasing and decreasing and how to express the answer using interval notation with the help of a number line. The function is increasing whenever the first derivative is positive or greater than zero. The function is decreasing whenever the first derivative is negative or less than zero. This video contains plenty of examples and practice problems.