设y=f(u),u=φ(x)则dy=?
问题描述:
设y=f(u),u=φ(x)则dy=?
答
y'=f'*φ'
故dy= f'(φ(x))*φ'(x) dx
设y=f(u),u=φ(x)则dy=?
y'=f'*φ'
故dy= f'(φ(x))*φ'(x) dx