Apply the Fundamental Theorem of Algebra to find the number of roots for the equation 12x−6x2+3x4=6x3+2x−x4 .(1 point)

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1 answer

To apply the Fundamental Theorem of Algebra, we first need to rewrite the equation in standard polynomial form. The given equation is:

\[ 12x - 6x^2 + 3x^4 = 6x^3 + 2x - x^4. \]

We can rearrange this equation by moving all terms to one side:

\[ 3x^4 + x^4 - 6x^2 - 6x^3 + 12x - 2x = 0. \]

Combining like terms, we get:

\[ 4x^4 - 6x^3 - 6x^2 + 10x = 0. \]

Now, we can factor out a common factor from all terms:

\[ 2x(2x^3 - 3x^2 - 3x + 5) = 0. \]

This gives us one root at \( x = 0 \).

Next, we need to find the number of roots of the cubic polynomial \( 2x^3 - 3x^2 - 3x + 5 \). A cubic polynomial (degree 3) can have:

  • 3 real roots,
  • 1 real root and 2 complex conjugate roots.

Thus, it will have a total of 3 roots (considering multiplicities).

Adding the root we found, we have:

  • 1 root from \( 2x = 0 \),
  • 3 roots from the cubic equation.

So, the total number of roots for the original equation is:

\[ 1 + 3 = 4. \]

Therefore, the total number of roots for the equation is 4.