Question

If x-2 is the factor of 3xsquare + kx+4 then the value of k

Answer 1

Answer:

k = 8

Note:

★ If (x - a) is a factor of the polynomial p(x) , then x = a is a zero of the polynomial p(x) and p(a) = 0 .

Solution:

Here,

The given quadratic polynomial is ;

3x² + kx + 4 .

Let the given quadratic polynomial be p(x) .

Thus,

p(x) = 3x² + kx + 4 .

Also,

It is given that , (x - 2) is a factor of the given quadratic polynomial p(x) , thus p(2) = 0.

Thus,

=> p(2) = 0

=> 3•2² + k•2 + 4 = 0

=> 12 + 2k + 4 = 0

=> 2k + 16 = 0

=> 2k = 16

=> k = 16/2

=> k = 8

Hence,

The required value of k is 8 .