设函数f(x)在点x0处可导,求lim(h→0)(f(x0+h)-f(x0-h))/2h的值
lim(h→0)(f(x0+h)-f(x0-h))/2h
=lim(h→0)(f(x0+h)-f(x0)+f(x0)-f(x0-h))/2h
=lim(h→0)[f(x0+h)-f(x0)]/2h+lim(h→0)[f(x0)-f(x0-h)]/2h
=1/2 f'(x0)+1/2f'(x0)
=f'(x0)
设函数f(x)在点x0处可导,求lim(h→0)(f(x0+h)-f(x0-h))/2h的值
lim(h→0)(f(x0+h)-f(x0-h))/2h
=lim(h→0)(f(x0+h)-f(x0)+f(x0)-f(x0-h))/2h
=lim(h→0)[f(x0+h)-f(x0)]/2h+lim(h→0)[f(x0)-f(x0-h)]/2h
=1/2 f'(x0)+1/2f'(x0)
=f'(x0)