For what value of k, – 4 is a zero of the polynomial x2 – x – (2k + 2)?
Given,
A polynomial x2 – x – (2k + 2)
– 4 is a zero of the given polynomial
As – 4 is the zero
So we get,
x2 – x – (2k + 2) = 0
( – 4)2 – ( – 4) – (2k + 2) = 0
16 + 4 – (2k + 2) = 0
20 – (2k + 2) = 0
– (2k + 2) = – 20
2k + 2 = 20
And
2k = 18
k = 18/9 = 2