public IExpressionNode Simplify()
{
LeftOperand = LeftOperand.Simplify();
RightOperand = RightOperand.Simplify();
if (!LeftOperand.ContainsVariable() && !RightOperand.ContainsVariable())
{
return(new Constant(this.Evaluate(null)));
}
else if (!LeftOperand.ContainsVariable() && RightOperand.ContainsVariable())
{
if (LeftOperand.Evaluate(null) == 0)
{
return(new Constant(0));
}
}
else if (LeftOperand.ContainsVariable() && !RightOperand.ContainsVariable())
{
if (RightOperand.Evaluate(null) == 0)
{
throw new DivideByZeroException();
}
if (RightOperand.Evaluate(null) == 1)
{
return(LeftOperand.DeepCopy());
}
}
return(this);
}
public IExpressionNode Derivate()
{
if (LeftOperand.ContainsVariable() && RightOperand.ContainsVariable())
{
return(new OperationMultiplication(
this.DeepCopy(),
new OperationMultiplication(
new FunctionLn(LeftOperand.DeepCopy()),
RightOperand.DeepCopy()).Derivate()));
}
else if (LeftOperand.ContainsVariable())
{
return(new OperationMultiplication(
new OperationMultiplication(
RightOperand.DeepCopy(),
new OperationPower(
LeftOperand.DeepCopy(),
new OperationSubtraction(RightOperand.DeepCopy(), new Constant(1))
)
),
LeftOperand.Derivate()
));
}
else if (RightOperand.ContainsVariable())
{
return(new OperationMultiplication(
new OperationMultiplication(
this.DeepCopy(),
new FunctionLn(LeftOperand.DeepCopy())
),
RightOperand.Derivate()
));
}
else
{
return(new Constant(0));
}
}
public bool ContainsVariable() => LeftOperand.ContainsVariable() || RightOperand.ContainsVariable();