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Using a given zero to write a polynomial as a product of linear

Using a given zero to write a polynomial as a product of linear-example-1
User Alb Bolush
by
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1 Answer

22 votes
22 votes

Given the polynomial:


g(x)=x^3+9x+20x+6

Where:

-3 is a zero of the polynomial.

Let's express the function as a product of linear factors.

Where:

x = -3

Equate to zero:

x + 3 = 0

Using synthetic division, let's divide the polynomial by -3:

Therefore, we have:


g(x)=(x+3)(x^2+6x+2)

Now,let's solve the expression(quotient) for x using the quadratic formula


x^2+6x+2

Apply the general quadratic equation:


\begin{gathered} ax^2+bx+c \\ \\ x^2+6x+2 \end{gathered}

WHere:

a = 1

b = 6

c = 2

Apply the quadratic formula:


x=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a}

Hence, we have:


\begin{gathered} x=\frac{-6\pm\sqrt[]{6^2-4(1)(2)}}{2(1)} \\ \\ x=\frac{-6\pm\sqrt[]{36-8}}{2} \\ \\ x=\frac{-6\pm\sqrt[]{28}}{2} \\ \\ x=(-6)/(2)\pm\frac{\sqrt[]{28}}{2} \\ \\ x=-3\pm\frac{\sqrt[]{4\cdot7}}{2} \\ \\ x=-3\pm\frac{2\sqrt[]{7}}{2} \\ \\ x=-3\pm\sqrt[]{7} \\ \\ x=-3-\sqrt[]{7},-3+\sqrt[]{7} \end{gathered}

Therefore, the polynomial g(x) as a product of linear factors are:


g(x)=(x+3)(x+3-\sqrt[]{7})(x+3+\sqrt[]{7})

ANSWER:


g(x)=(x+3)(x+3-\sqrt[]{7})(x+3+\sqrt[]{7})

Using a given zero to write a polynomial as a product of linear-example-1
User Yshchohaleu
by
2.8k points
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