Question

No Polinômio p(x)=x³-kx+x+1; Determine k se:

a) p(1)=0
b) p(3)=1
c) p(-2)=5

Answer 1

 
 

No Polinômio p(x)=x³-kx+x+1; Determine k se:

a) p(1)=0

x³-kx+x+1 = 0 ==> 1³-k.1+1+1=0==> 1-k+2= 0 ==> k = 3

b) p(3)=1

 3³-k.3 + 3 +1=1==>27-3k+4= 1 ==> 3k = - 31+1 ==> k = - 30/3==> k = -10

c) p(-2)=5

 (-2)³-k.(-2)1+(-2)+1=5==> -8+2k-2+1= 5 ==> 2k = 5+9 ==> 2k=14==> k = 7