Question

Se P(x) = x3 + 2x2 + kx – 2 eP(2) = 0,
então k vale:

Answer 1

P(x) = x³ + 2x² + kx - 2

P(2) = 0

2³ + 2.2² + k.2 - 2 = 0
8 + 2.4 + 2k - 2 = 0
8 + 8 - 2 + 2k = 0
14 + 2k = 0
2k = 0 - 14
2k = -14
k = - 14/2
k = - 7