# Finding the Arctangent of Specified Number in Golang

Go language provides inbuilt support for basic constants and mathematical functions to perform operations on the numbers with the help of the math package. You are allowed to find the arctangent of the specified number with the help of Atan() function provided by the math package. So, you need to add a math package in your program with the help of the import keyword to access Atan() function.

Syntax:

`func Atan(y float64) float64`
• If you pass +Inf or -Inf in this function, then this function will return +Pi/2 or -Pi/2.
• If you pass 0 in this function, then this function will return 0.

Example 1:

 `// Golang program to illustrate how ` `// to find arctangent of the given number ` ` `  `package main ` ` `  `import ( ` `    ``"fmt"` `    ``"math"` `) ` ` `  `// Main function ` `func main() { ` ` `  `    ``// Finding arctangent of ` `    ``// the given value ` `    ``// Using Atan() function ` `    ``res_1 := math.Atan(1) ` `    ``res_2 := math.Atan(math.Inf(-3)) ` `    ``res_3 := math.Atan(0) ` `    ``res_4 := math.Atan(math.NaN()) ` ` `  `    ``// Displaying the result ` `    ``fmt.Printf(``"Result 1: %.1f"``, res_1) ` `    ``fmt.Printf(``"\nResult 2: %.1f"``, res_2) ` `    ``fmt.Printf(``"\nResult 3: %.1f"``, res_3) ` `    ``fmt.Printf(``"\nResult 4: %.1f"``, res_4) ` `} `

Output:

```Result 1: 0.8
Result 2: -1.6
Result 3: 0.0
Result 4: NaN
```

Example 2:

 `// Golang program to illustrate how ` `// to find arctangent of the given number ` `package main ` ` `  `import ( ` `    ``"fmt"` `    ``"math"` `) ` ` `  `// Main function ` `func main() { ` ` `  `    ``// Finding arctangent ` `    ``// of the given value ` `    ``nvalue_1 := math.Atan(1) ` `    ``nvalue_2 := math.Atan(-3) ` ` `  `    ``// Sum of the given values ` `    ``res := nvalue_1 + nvalue_2 ` ` `  `    ``// Displaying results ` `    ``fmt.Printf(``"%.1f + %.1f = %.1f"``,  ` `            ``nvalue_1, nvalue_2, res) ` ` `  `} `

Output:

`0.8 + -1.2 = -0.5`

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