math: add a Sqrt example

Change-Id: I259e25b9d0b069912053a250e9739e04fafca54d
Reviewed-on: https://go-review.googlesource.com/48892
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/math/example_test.go b/src/math/example_test.go
new file mode 100644 (file)
index 0000000..12e9876
--- /dev/null
+++ b/src/math/example_test.go
@@ -0,0 +1,20 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package math_test
+
+import (
+       "fmt"
+       "math"
+)
+
+func ExampleSqrt() {
+       const (
+               a = 3
+               b = 4
+       )
+       c := math.Sqrt(a*a + b*b)
+       fmt.Printf("%.1f", c)
+       // Output: 5.0
+}