What is the length of the curve with parametric equations x = 1 - 2cos(t), y = 2 - 2sin(t) from t = 0 to t = π ?

Question

What is the length of the curve with parametric equations x = 1 - 2cos(t), y = 2 - 2sin(t) from t = 0 to t = π?

A	8
B	4
C	8π
D	2π

Answer 1

s = ∫₀^π(x'²(t) + y'²(t))^1/2dt = ∫₀^π(4sin²(t) + 4cos²(t))^1/2dt = 2t₀^π = 2π

Answer is D