public void DerivativeTest3() { // cos(2x) Number num = new Number(2); Variable x = new Variable("x"); Mul mul = new Mul(num, x); IExpression exp = new Cos(mul); IExpression deriv = exp.Differentiate(); Assert.AreEqual("-(sin(2 * x) * (2 * 1))", deriv.ToString()); num.Value = 7; Assert.AreEqual("cos(7 * x)", exp.ToString()); Assert.AreEqual("-(sin(2 * x) * (2 * 1))", deriv.ToString()); }
public void CosDerivativeTest3() { // cos(2x) var num = new Number(2); var x = new Variable("x"); var mul = new Mul(num, x); var exp = new Cos(mul); var deriv = Differentiate(exp); Assert.Equal("-(sin(2 * x) * 2 * 1)", deriv.ToString()); num.Value = 7; Assert.Equal("cos(7 * x)", exp.ToString()); Assert.Equal("-(sin(2 * x) * 2 * 1)", deriv.ToString()); }