public void PartialDerivativeTest2()
{
// (yx) ^ 3
IExpression exp = new Pow(new Mul(new Variable("y"), new Variable("x")), new Number(3));
IExpression deriv = exp.Differentiate(new Variable("y"));
Assert.AreEqual("(1 * x) * (3 * ((y * x) ^ (3 - 1)))", deriv.ToString());
}
public void DerivativeTest3()
{
// x ^ 3
Variable x = new Variable("x");
Number num1 = new Number(3);
IExpression exp = new Pow(x, num1);
IExpression deriv = exp.Differentiate();
Assert.AreEqual("1 * (3 * (x ^ (3 - 1)))", deriv.ToString());
num1.Value = 4;
Assert.AreEqual("x ^ 4", exp.ToString());
Assert.AreEqual("1 * (3 * (x ^ (3 - 1)))", deriv.ToString());
// 2 ^ (3x)
Number num2 = new Number(2);
num1 = new Number(3);
Mul mul = new Mul(num1, x.Clone());
exp = new Pow(num2, mul);
deriv = exp.Differentiate();
Assert.AreEqual("(ln(2) * (2 ^ (3 * x))) * (3 * 1)", deriv.ToString());
num1.Value = 4;
Assert.AreEqual("2 ^ (4 * x)", exp.ToString());
Assert.AreEqual("(ln(2) * (2 ^ (3 * x))) * (3 * 1)", deriv.ToString());
}
public void DerivativeTest1()
{
IExpression exp = new Pow(new Variable("x"), new Number(3));
IExpression deriv = exp.Differentiate();
Assert.AreEqual("1 * (3 * (x ^ (3 - 1)))", deriv.ToString());
}
public void DerivativeTest2()
{
// 2 ^ (3x)
IExpression exp = new Pow(new Number(2), new Mul(new Number(3), new Variable("x")));
IExpression deriv = exp.Differentiate();
Assert.AreEqual("(ln(2) * (2 ^ (3 * x))) * (3 * 1)", deriv.ToString());
}
public void PartialDerivativeTest3()
{
IExpression exp = new Pow(new Variable("x"), new Number(3));
IExpression deriv = exp.Differentiate(new Variable("y"));
Assert.AreEqual("0", deriv.ToString());
}