For what value of k, (−4) is a zero of the polynomial x2 − x − (2k + 2)?
Answers & Comments
ankur0022
Hey Mate.. Let p(x) = x2 − x − (2k + 2).
If (−4) is a zero of p(x), then p (−4) = 0.
p(−4) = 0
Þ (−4)2 − (−4) − 2k − 2 = 0
Þ 16 + 4 − 2k − 2 = 0
Þ 18 − 2k = 0
Þ 2k = 18
Þ k = 9
Thus, the required value of k is 9.
4 votes Thanks 7
ishika1905
Let p(x)= x2 -x-(2k+2) given zero is -4 so, p(-4)=(-4)2-(-4)-(2k+2)=0 16+4-2k-2=0 20-2k-2=0 18-2k=0 -2k=-18 2k=18 k=18/2 k=9 value of k is 9
Answers & Comments
Let p(x) = x2 − x − (2k + 2).
If (−4) is a zero of p(x), then p (−4) = 0.
p(−4) = 0
Þ (−4)2 − (−4) − 2k − 2 = 0
Þ 16 + 4 − 2k − 2 = 0
Þ 18 − 2k = 0
Þ 2k = 18
Þ k = 9
Thus, the required value of k is 9.
given zero is -4
so,
p(-4)=(-4)2-(-4)-(2k+2)=0
16+4-2k-2=0
20-2k-2=0
18-2k=0
-2k=-18
2k=18
k=18/2
k=9
value of k is 9