Question

Sa se rezolve:
f:R-R ;f(x)= 2x-8
a) f(1)+f(2)+....+f(100)
b) f(1)×f(2)×....×f(100)
Va rog ajutati-ma repede OFER COROANA

Answer 1

f(1)=-6; f(2)=-4; f(3)=-2; f(4)=0; f(5)=2; f(6)=4; f(7)=6; f(8)=8... ,,f(100)=192 =>S=-6-4-2+0+2+4+6+8+10+.... +192=> S=8+10+....192; si suma scrisa invers S=192+190+......8 adunam cele 2 sume => 2S=200+200...+200 (avem 93 termeni))=> S=200*93/2=100*93=9300. . Pridusul este egal cu 0 deoarece unil din factori este 0