Calculate partial derivatives of multivariable functions with step-by-step solutions and detailed explanations.
Supported: +, -, *, ^, sin, cos, tan, ln, e^x, parentheses
Use ^ for exponents (e.g., x^2 for x²)
Multiplication can be implicit (xy) or explicit (x*y)
Trigonometric functions: sin(x), cos(x), tan(x)
Exponential and logarithmic: e^x, ln(x)
Variables are treated as independent unless specified