Question

Diketahui X2 + (p+1)x +8 =0, mempunyai akar-akar x1 dan x2 dan tentukan p jika x1 = 1/2 x2!

Answer 1

X^2 + (p+1)x + 8 = 0
X1= 1/2 X2

X1 x X2 = c/a = 8 ( substitusi X1 = 1/2 X2 nya)
1/2 X2 x X2 = 8
(X2)^2 = 8 x 2 = 16
maka, X2 = 4

jika X2 = 4 maka,
X1 = 1/2X2
X1 = 1/2 (4)
X1 = 2

X1 + X2 = -b/a = -(p + 1)
2 + 4 = -p - 1
6 = -p - 1
-p = 6 + 1 = 7
p = -7
maka p= -7