Question

fie functia f:R-R,f(x)=2x-1. sa se calculeze f(1)+f(2)+f(3)........f(2012).

Answer 1

f(x)=2x-1
f(1)= 1
f(2)=3
f(3)=5
.....
f(2012)=4023
Termenii sunt in progresie aritmetica cu ratia= 2
S=(a1+an)*n /2
an=a1+(n-1)*r
an= 1+(2012-1)*2= 1+ 4022=4023
S=(a1+an)*n/2
S= (1+4023)*2012/ 2 = 4048144