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Task/Arithmetic-geometric-mean/FreeBASIC/arithmetic-geometric-mean.freebasic

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+' version 16-09-2015
+' compile with: fbc -s console
+
+Function agm(a As Double, g As Double) As Double
+
+    Dim As Double t_a
+
+    Do
+        t_a = (a + g) / 2
+        g = Sqr(a * g)
+        Swap a, t_a
+    Loop Until a = t_a
+
+    Return a
+
+End Function
+
+' ------=< MAIN >=------
+
+Print agm(1, 1 / Sqr(2) )
+
+' empty keyboard buffer
+While InKey <> "" : Wend
+Print : Print "hit any key to end program"
+Sleep
+End