Question

Find the value of 'k', for which the polynomial x^3-3x^2+3x+k has 3 as its zero.

Answer 1

Hey !

p(x) = x³ - 3x² + 3x + k

p(3) = 0

p(3) = 3³ - 3 × 3² + 3 × 3 + k
       = 27 -  27 + 9 + k = 0
       = 9 + k = 0
       
   k = -9

Hope this helps you !!

Answer 2

Given:

x³-3x²+3x+k

The zero of the polynomial is 3.

To Find:

The value of k

Solution:

p(x) = x³-3x²+3x+k

It is given that 3 is zero. So, substituting x with 3.

zero of the polynomial is x-3

p(3) = (3)³ - 3 × (3)² + 3 × 3 + k

solving the cubes and squares.

p(3) = 27 - 27 + 9 + k = 0

      = 9 + k = 0

   k = -9