diff --git a/rpn b/rpn
index 927db1f..e8ed2f4 100755
--- a/rpn
+++ b/rpn
@@ -43,6 +43,20 @@ while (<>) {
 	} elsif (m{^ld$}) {
 	    my $x = pop @stack;
 	    push @stack, log($x) / log(2);
+	} elsif (m{^sin$}) {
+	    my $x = pop @stack;
+	    push @stack, sin($x);
+	} elsif (m{^cos$}) {
+	    my $x = pop @stack;
+	    push @stack, cos($x);
+	} elsif (m{^tan$}) {
+	    my $x = pop @stack;
+	    push @stack, tan($x);
+	} elsif (m{^e$}) {
+	    push @stack, exp(1);
+	} elsif (m{^exp$}) {
+            my $x = pop @stack;
+	    push @stack, exp($x);
 	} elsif (m{^0x[0-9a-fA-F]+$}) {
             no warnings 'portable';
 	    push @stack, hex($_);