[Citat] 2 c
I0+I1+I2<e^x => 1+x+(x^2)<e^x =>
=> 1+x+(x^2)-e^x<0 pentru orice x apartine[0,+inf)
notam, f(x)=1+x+(x^2)-e^x definita pe[0;+inf)->R
f'(x)=1+x-e^x
avem relatia e^x>1+x =>1+x-e^x<0 pentru orice x apartine [0,+inf)
=> f'(x)<0 =>f descrescatoare pe [0,+inf)
f'(x)=0 =>x=0 => x=o punct de maxim =>f(0)=0 valoare maxima
=> f(x)<0 => 1+x+(x^2)-e^x<0 =>1+x+(x^2)<e^x =>I0+I1+I2<e^x
pentru orice x apartine [0,+inf) |
multumesc nino , eleganta "abordare"
