add tests for IMCOSH / IMCOS

cell/.unit-tests/FormulaTests.js

@@ -2032,6 +2032,18 @@ $( function () {
         strictEqual( oParser.calculate().getValue(), ((Math.E + 1 / Math.E) / 2) );
     } );
 
+	test( "Test: \"IMCOSH\"", function () {
+		oParser = new parserFormula( 'IMCOSH("4+3i")', "A2", ws );
+		ok( oParser.parse(), 'IMCOSH("4+3i")' );
+		strictEqual( oParser.calculate().getValue(), "-27.03494560307422+3.8511533348117766i", 'IMCOSH("4+3i")' );
+	} );
+
+	test( "Test: \"IMCOS\"", function () {
+		oParser = new parserFormula( 'IMCOS("1+i")', "A2", ws );
+		ok( oParser.parse(), 'IMCOS("1+i")' );
+		strictEqual( oParser.calculate().getValue(), "0.8337300251311491-0.9888977057628651i", 'IMCOS("1+i")' );
+	} );
+
     test( "Test: \"TANH\"", function () {
 
         oParser = new parserFormula( "TANH(0)", "A2", ws );

cell/model/FormulaObjects/engineeringFunctions.js

@@ -479,7 +479,7 @@
 		}, Cosh: function () {
 			if (this.img) {
 				var a = Math.cosh(this.real) * Math.cos(this.img);
-				this.img = -( Math.sinh(this.real) * Math.sin(this.img) );
+				this.img = Math.sinh(this.real) * Math.sin(this.img);
 				this.real = a;
 			} else {
 				this.real = Math.cosh(this.real);