Challenging +1.2 This is a standard arc length parametric question requiring computation of √((dx/dt)² + (dy/dt)²) and integration. The derivatives involve straightforward differentiation (exponentials and polynomials), and the resulting integrand simplifies to a perfect square that integrates cleanly. While it requires careful algebraic manipulation and is a Further Maths topic, it follows a completely standard template with no conceptual surprises, making it moderately above average difficulty.