Răspuns:
9. inlocuiesti x cu 0, -6, 6 si 12
f(0)= 0-3= -3 f(-6)= -6-3=-9
f(6)= 6-3= 3 f(12)=12-3= 9
f(-6)+f(0) + f(6)+f(12)= -3- 9+3+9= -12+12= 0
11. se inlocuieste x cu 0, 1, 2,3,4
f(0)+ f(1)+f(2)+f(3)+f(4)= [tex](\frac{1}{2} )^{0} + (\frac{1}{2} )^{1} + (\frac{1}{2} )^{2} (\frac{1}{2} )^{3} + (\frac{1}{2} )^{4}[/tex]= 1 + [tex]\frac{1}{2} + \frac{1}{4} + \frac{1}{8} + \frac{1}{16}[/tex] aducem la acelasi numitor 16
= (16+8+4+2+1)/16= 31/16
