Function values can be positive or negative, and they can increase or decrease as the input increases. Here we introduce these basic properties of functions.

Highlight intervals on the domain of a function where it's only increasing or only decreasing.

Review how we use differential calculus to find the intervals where a function increases or decreases.

You don't know what the graph looks like because you aren't given it. You do, however, know what the derivative graph looks like, and looking at that alone lets you know where the graph is …

Finding the positive or negative intervals of a function from its graph. Created by Sal Khan.

The critical points themselves won't tell you if the function is decreasing or increasing. You can either go for the second derivative or check the behaviour of the function in the neighbourhood.

Find the intervals in which a function (given algebraically) is increasing or decreasing.

Identify intervals on the domain of a function where it's entirely positive or entirely negative.

Function values can be positive or negative, and they can increase or decrease as the input increases. Here we introduce these basic properties of functions.

Knowing the sign of a polynomial function between two zeros can help us fill in some of the gaps. In this article, we'll learn how to determine the intervals over which a polynomial is positive or …