Question

Check whether -2 is a root of the polynomial 3x3+5x2+6x+4

Answer 1

Q. Check whether -2 is a root of the polynomial $3x^3 + 5x^2 + 6x + 4$

Here is your answer friend:

We know that to satisfy a root of any polynomial, the polynomial value must be 0.

let the polynomial be p( x ),

Then,

p( x ) = $3x^3 + 5x^2 + 6x + 4$

p( - 2) = $3(-2)^3 + 5(-2)^2 + 6(-2) + 4$

         = 3 × (- 8) + 5 × 4 - 12 + 4

         = - 24 + 20 - 12 + 4

         = - 12

As the value of x in the polynomial p( x ) is not 0,

It is not a root of the polynomial.

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