## What is the ATAN function in Excel?

The **ATAN **function is one of the math functions of Excel. It returns the arctangent of a number in radians, in the range Of **-pi/2 to Pi/2**.

We can find this function in the **Math&trig** section of the insert function Tab.

## How to use **ATAN **function in excel

- Click on an empty cell (like F5 )

2. Click on the **fx **icon (or press** shift+F3**)

3. In th**e insert function** tab you will see all functions

4. Select **math and trig** category

5. Select the** ATAN **function

6. Then select **ok**

7. In the function arguments Tab you will see th** e ATAN **function

8. In the Number section you can enter the** tangent of the angle** you want

9. You will see the result in the formula result section ( **ATAN **(0)=0)

## Examples of **ATAN** function in excel

**Example 1:**

**How to use ATAN function in excel**

You can see examples of ATAN function below:

**atan**(-1) ----->>>>answer is -0.785
**atan**(-0.5) ----->>>>answer is -0.463
**atan**(0) ----->>>>answer is 0
**atan**(0.5) ----->>>>answer is 0.463
**atan**(1) ----->>>>answer is 0.785

math.atan(a)

### How to plot Y=ATAN(X) with python code in excel

```
import math
import numpy as np
import matplotlib.pyplot as plt
x =np.linspace(–2,+2, 100)
lenx=len(x)
y=[]
for i in range(lenx):
y.append(math.atan(x[i]))
i +=1
plt.plot(x,y)
plt.show()
```

## What is the purpose of **ATAN** function?

It returns the arctangent of a number in radians, in the range Of **-pi/2 to Pi/2**.

## What is the Return value of **ATAN** function?

It returns a number.

## How many arguments does **ATAN** function have?

This function has just **1** Argument.

The **argument **of ATAN function is **number**.

In the Number section you can enter the** tangent of the angle** you want

The argument of ATAN function is **required **and not optional.

```
ATAN(number) = number
```

## Which version of excel supports **ATAN** function?

This function is available for all excel **versions **(2003-2019)