# What Does Rate Of Change Mean In Math

Rate of change is a measure of how fast something is changing. In mathematics it is usually denoted by the symbol “d” followed by a variable. For example if we take the function f(x) = x2 then the rate of change of f with respect to x is represented by the symbol df/dx. This is read as “dee f dee x” and means “the derivative of f with respect to x”.

The rate of change tells us how fast a function is increasing or decreasing at a given point. It is the slope of the tangent line to the graph of the function at that point. The tangent line is the line that just touches the graph of the function at that point and is parallel to the x-axis.

We can calculate the rate of change of a function at a point by taking the derivative of the function at that point. The derivative of a function is a measure of how the function changes as the input changes. In the case of our example function f(x) = x2 the derivative is just 2x. This means that the rate of change of f(x) is 2x. So at the point x = 1 the rate of change is 2(1) = 2. At the point x = 2 the rate of change is 2(2) = 4 and so on.

The rate of change can be used to find the equation of the tangent line to the graph of a function at a given point. For example if we take the point (11) on the graph of f(x) = x2 then the tangent line to the graph at that point has a slope of 2. This means that the equation of the tangent line is y = 2x + b where b is the y-intercept.

The rate of change can also be used to find the concavity of a function at a given point. A function is concave up if the rate of change is increasing and concave down if the rate of change is decreasing. For example the function f(x) = x2 is concave down at the point x = 0 since the rate of change is 2x which is negative for small values of x.