1 files changed, 29 insertions, 0 deletions
diff --git a/misc/pascal/tests/src/101-cosine.pas b/misc/pascal/tests/src/101-cosine.pas
new file mode 100644
index 0000000000..b2797fcb90
--- /dev/null
+++ b/misc/pascal/tests/src/101-cosine.pas
@@ -0,0 +1,29 @@
+{ compute the cosine using the expansion:
+  cos(x) = 1 - x**2/(2*1) + x**4/(4*3*2*1) - ... }
+
+program cosine(input, output);
+
+const
+   eps = 1e-14;
+
+var
+   x, sx, s, t : real;
+   i, k, n     : integer;
+
+begin
+   write('Number of cosines: ');
+   read(n);
+   for i:=1 to n do
+   begin
+      write(n, '. Enter radians: ');
+      read(x);
+      t := 1; k := 0; s := 1; sx := sqr(x);
+      while abs(t) > eps*abs(s) do
+      begin
+	 k := k+2;
+	 t := -t*sx/(k*(k-1));
+	 s := s+t;
+	 writeln('   cos(', x, ')=', s, ' interation=', k div 2)
+      end
+   end
+end.