Akar akar persamaan 2x³-3x²+4x+2=0 adalah p, q,dan r. Tentukan nilai 1/pq+1/qr+1/pr.

jawab

2x³ - 3x² + 4x + 2  = 0
a= 2
b = - 3
c = 4
d= 2

p + q + r = -b/a = 3/2
p q r = - d/a = -2/2 = -1

1/(pq) + 1/(qr) + 1/(pr) = (p + q + r) /(pqr)
= (3/2) / (-1)
= - 3/2