Question

x³+4x²+4x is a quadratic polynomial​

Answer 1

Answer:

no

Step-by-step explanation:

because in quadratic polynomial

highest power should be 2.

and here highest power is 3 so,

it is not a quadratic polynomial

Answer 2

Answer:

yes its correct see the eg given

Step-by-step explanation:

x^3 - 27 = (x - 3)(x^2 + 3x + 9)

If x^3 + 4x^2 + 12x + k is divisible by x^2 + 3x + 9, then,

x^3 + 4x^2 + 12x + k = (x^2 + 3x + 9)(x - a), where a is a real number.

x^3 + 4x^2 + 12x + k = x^3 - ax^2 + 3x^2 - 3ax + 9x - 9a

x^3 + 4x^2 + 12x + k = x^3 + (3 - a)x^2 + (9 - 3a)x - 9a

By correspondence,

4 = 3 - a, so a = - 1

9 - 3a = 12, so a = - 1

k = - 9a

But we have already determined that a = -1.

Therefore, k = -9 (-1) = 9