Question

Find the value of k if x -1is a factor of 4x3 +3x2 - 4x + k

Answer 1

Given f(x) =  4x^3 + 3x^2 - 4x + k.

Given x - 1 is a factor of f(x).

By remainder theorem,

x - 1 = 0

x = 1.

According to remainder theorem f(1) = 0, we get

f(1) = 4(1)^3 + 3(1)^2 - 4(1) + k = 0

     = 4 + 3 - 4 + k = 0

     k + 3 = 0

    k = -3.


Therefore the value of k = -3.


Hope this helps!

Answer 2

Hiiii friend,


(X-1) is a factor of the given polynomial.


(X-1) = 0


X = 1


P(X) = 4X³+3X²-4X+K

P(1) = 4 × (1)³ + 3 × (1)² - 4 × 1 + K


=> 4 × 1 + 3 × 1 -4 + K

=> 4 + 3 - 4 + K = 0

=> K +3 = 0

=> K = -3

HOPE IT WILL HELP YOU...... :-)