Question

f:(x) - R f(x) = x - 2 ln x Sa se arate ca f(1) +f ' (1) = 0

Answer 1

f(1)=1-2ln1= 1 deoarece ln1=0
f'(x)=1-2/x deoarece x'=1 si (lnx)'=1/x
f'(1)=1-2=-1
f(1)+f'(1)=1-1=0