Question

Verify that the numbers given alongside the cubic polynomials below are their zeroes.
Also verify the relationship between the zeroes and the coefficients in each case

(ii) x2 + 4x² + 5x – 2;(1, 1, 1)​

Answer 1

Answer:

(ii) x

3

−4x

2

+5x−2;2,1,1

p(x)=x

3

−4x

2

+5x−2 .... (1)

Zeroes for this polynomial are 2,1,1

Substitute x=2 in equation (1)

p(2)=2

3

−4×2

2

+5×2−2

=8−16+10−2=0

Substitute x=1 in equation (1)

p(1)=x

3

−4x

2

+5x−2

=1

3

−4(1)

2

+5(1)−2

=1−4+5−2=0

Therefore, 2,1,1 are the zeroes of the given polynomial.