Question: A curve is defined by the parametric equations x = f(t) and y = g(t), where f(t) and g(t) are differentiable functions. Which of the following gives the length of the curve from t = a to t = b?
1) ∫[a,b] √(f'(t)² + g'(t)²) dt
2) ∫[a,b] √(f(t)² + g(t)²) dt
3) ∫[a,b] (f'(t) + g'(t)) dt
4) ∫[a,b] (f(t) + g(t)) dt