Question

Daca f:R->R, f(x)=2x-1 .Calculati f(1)+f(2)+f(3)+...f(50)

Answer 1

Explicație pas cu pas:

f(1)= 2-1

f(1)=1

f(2)=4-1

f(2)=3

f(3)=6-1

f(3)=5

...

f(50)=100-1

f(50)=99

1+3+5+...+99

=1+2+3+...+100- 2+4+6+...+100

=100×101/2 - 2(1+2+3+...+50)

=50×101-50×51

=50(101-51)

=50×50

=250