Question

If (2x-1) is a factor of the polynomial
P(x) = 2x^3-5x^2- Kx +3
find value of k.

Answer 1

K = 4

Explanation:

If (2x-1) is a factor, that means that when x =
`(1)/(2)`, the function equals 0

`0 = 2((1)/(2))^3 -5((1)/(2))^2-K((1)/(2))+3\\-3 = (1)/(4) -(5)/(4) -(K)/(2)\\ -3 = -1 - (K)/(2) \\-2 = (-K)/(2) \\K = 4`