tryIntegrate method

@override Expression? tryIntegrate(Expression expr, Variable v)

Attempts to integrate the expression Returns null if this strategy cannot handle the expression

Implementation

@override
Expression? tryIntegrate(Expression expr, Variable v) {
  // Handle solo functions that require IBP (implied * 1)
  if (_isLogarithmic(expr) || _isInverseTrig(expr)) {
    return _applyByParts(expr, Literal(1), v);
  }

  if (expr is! Multiply) return null;

  final left = expr.left;
  final right = expr.right;
  // ... rest of method (unchanged logic below this point for Multiply)

  // Note: Re-implementing the switch logic here is risky with find/replace if I don't give enough context
  // So I will only replace the top Check.

  // Pattern 1: ∫ln(x)·x^n dx
  if (_isLogarithmic(left) && _isPolynomial(right, v)) {
    return _applyByParts(left, right, v);
  }
  if (_isPolynomial(left, v) && _isLogarithmic(right)) {
    return _applyByParts(right, left, v);
  }

  // Pattern 2: ∫asin(x)·x^n dx
  if (_isInverseTrig(left) && _isPolynomial(right, v)) {
    return _applyByParts(left, right, v);
  }
  if (_isPolynomial(left, v) && _isInverseTrig(right)) {
    return _applyByParts(right, left, v);
  }

  // Pattern 3: ∫x·sin(x) dx or ∫x·cos(x) dx
  if (_isPolynomial(left, v) && _isTrigonometric(right)) {
    return _applyByParts(left, right, v);
  }
  if (_isTrigonometric(left) && _isPolynomial(right, v)) {
    return _applyByParts(right, left, v);
  }

  // Pattern 5: ∫x·e^x dx
  if (_isPolynomial(left, v) && _isExponential(right)) {
    return _applyByParts(left, right, v);
  }
  if (_isExponential(left) && _isPolynomial(right, v)) {
    return _applyByParts(right, left, v);
  }

  return null;
}