when x^2+ax-b is divided by x+2, the remainder is -7. when ax^2-bx+1 is divided by x-2,the remainder is 3. find the values of a and b.
係咪應該用remainder theorem...但係我計唔到…
kylau
2007-06-04 21:58
just use remainder theorem, two eqs, two unknowns. ---------- when x^2+ax-b is divided by x+2, the remainder is -7.
sub x = -2, get 4-2a-b = -7 --------------------------------- when ax^2-bx+1 is divided by x-2, the remainder is 3.
sub x = 2, get 4a-2b+1 = 3
then do it yourself
影
2007-06-04 22:05
引用第1樓kylau於2007-06-04 21:58發表的“”: just use remainder theorem, two eqs, two unknowns. ---------- when x^2+ax-b is divided by x+2, the remainder is -7. sub x = -2, get 4-2a-b = -7 .......