Question

高等数学-参数方程求导

Answer 1

简单计算一下即可，答案如图所示

Answer 2

Answer 3

Answer 4

x=f'(t)，y=tf'(t)-f(t)，则dx=f''(t)dt，dy=[f'(t)+tf''(t)-f'(t)]dt=tf''(t)，所以dy/dx=tf''(t)/f''(t)=t，d²y/dx²=d(dy/dx)/dx=d(t)/dt/(dx/dt)=1/f''(t)。