Question

What is the range of the cosine function?

Short answer

The range of cosine function is :-

$-1to1$

Step-by-step solution

Step 1. Given Information

We have to find the range of a cosine function.

The range of a function is the set of its possible output values.

We will draw a graph of cosine function using graphing utility, then calculate its range.

Step 2. Graph of Cosine function 

By using graphing utility we can draw the graph of cosine function as following :-

Step 3. Analyzing Range

We draw the graph of cosine function as following :-

We can see that all the values of $y$for all values of $x$lies between $-1$and $1$.

So we can conclude that range of cosine function is$-1to1$.