math, path: minor comment fixes

R=r
CC=golang-dev
https://golang.org/cl/444043

src/pkg/math/ldexp.go

@@ -5,7 +5,7 @@
 package math
 
 // Ldexp is the inverse of Frexp.
-// It returns frac × 2<sup>exp</sup>.
+// It returns frac × 2^exp.
 func Ldexp(frac float64, exp int) float64 {
 	// TODO(rsc): Remove manual inlining of IsNaN, IsInf
 	// when compiler does it for us

src/pkg/path/path.go

@@ -115,7 +115,7 @@ func Split(path string) (dir, file string) {
 	return "", path
 }
 
-// Join joins any number of path elemets into a single path, adding a
+// Join joins any number of path elements into a single path, adding a
 // separating slash if necessary.  All empty strings are ignored.
 func Join(elem ...string) string {
 	for i, e := range elem {