Question

lim x tends to 1 f(x)-f(1)÷x-1

Answer 1

limx-->1 f(x)-f(1)/x-1

Put x =0
=> 0/0 form
now applying l hospital rule
limx-->1 f'(x) -0/1-0
=> limx-->1 f(x)-f(1)/x-1 = f'(1)