Diketahui x1 dan x2 adalah akar-akar persamaan x2 - 2x + 4 = 0. Pers. kuadrat yg akar-akarnya (x1 + x2) dan (x1.x2) adalah...
pilihan jawaban
x2 - 6x + 8 = 0
x2 - 6x - 8 = 0
x2 + 6x + 8 = 0
x2 - 4x + 8 = 0
x2 + 4x - 8 = 0
pilihan jawaban
x2 - 6x + 8 = 0
x2 - 6x - 8 = 0
x2 + 6x + 8 = 0
x2 - 4x + 8 = 0
x2 + 4x - 8 = 0
x1x2=c/a=4/1=4
x1+x2=
(x1+x2)+(x1x2)
= (2)+(4)
=6
x1x2
(x1+x2)(x1x2)
=(2)(4)
=8
x²-(x1+x2)x+x1x2
x²-6x+8