你
告诉
它将这些表达式分配给这些变量!
x (t) =
R * cosθ(t))
y (t) =
R * sin(θ(t))
Dx (t) =
- r * sinθ(t)) * diff(θ(t), t)
Dy (t) =
R * cosθ(t)) * diff(θ(t), t)
D2x (t) =
- R * cos(θ(t)) * diff(θ(t), t) ^ 2 - R * sin(θ(t)) * diff(θ(t), t, t)
D2y (t) =
R * cosθ(t)) * diff(θ(t), t, t) - R * sin(θ(t)) * diff(θ(t), t) ^ 2
