If 5 is a zero of x3+kx2+2x+8. Find k.

Let px = x3 + kx2+2x+8Since, 5 is a zero of px, then      p5 = 053 + k52 + 25 + 8 = 0125 + 25k + 10 + 8 = 025k + 143 = 025k = -143k = -14325

  • 2
5 is a zero
p(5)=(5)3+k(5)2+2(5)+8=0
125+25k+10+8=0
143+25k=0
25k=-143
k=-143/25=6.72
  • 2
What are you looking for?