如果我有两个参数方程,例如x = 2*t
和y = t**2 - 3
,我可以按如下方式区分它们:
>>> x, y, t = symbols('x, y, t')
>>> x = 2*t
>>> y = t**2 - 3
>>> diff(y)/diff(x)
t
获得二阶导数:
>>> (diff(x,t,1)*diff(y,t,2) - diff(y,t,1)*diff(x,t,2)) / diff(x,t,1)**3
1/2
我可以用同一个快捷方式来计算这个吗?
将这个包装在函数中是我应该做的事情吗?
>>> def second_derivative(x,y):
>>> return (diff(x,t,1)*diff(y,t,2) - diff(y,t,1)*diff(x,t,2)) / diff(x,t,1)**3
然后它变成:
>>> second_derivative(2*t, t**2 - 3)
1/2
答案 0 :(得分:-1)
我选择创建自定义函数:
>>> def second_derivative(x,y):
>>> return (diff(x,t,1)*diff(y,t,2) - diff(y,t,1)*diff(x,t,2)) / diff(x,t,1)**3
这就是这样称呼的:
>>> second_derivative(2*t, t**2 - 3)
1/2