Question

Find all rational zeros of the polynomial, and write the polynomial in factored form. P(x)=3x^{5}-14x^{4}-14x^{3}+36x^{2}+43x+10

Polynomial factorization
ANSWERED
asked 2021-05-20
Find all rational zeros of the polynomial, and write the polynomial in factored form.
\(\displaystyle{P}{\left({x}\right)}={3}{x}^{{{5}}}-{14}{x}^{{{4}}}-{14}{x}^{{{3}}}+{36}{x}^{{{2}}}+{43}{x}+{10}\)

Answers (1)

2021-05-22

Step 1
Given polynomial is, \(\displaystyle{P}{\left({x}\right)}={3}{x}^{{{5}}}-{14}{x}^{{{4}}}-{14}{x}^{{{3}}}+{36}{x}^{{{2}}}+{43}{x}+{10}\)
By using rational root theorem,
\(-\frac{1}{1} \text{is the root of the expression, so factor out}\ x+1\).
\(\displaystyle{\frac{{{3}{x}^{{{5}}}-{14}{x}^{{{4}}}-{14}{x}^{{{3}}}+{36}{x}^{{{2}}}+{43}{x}+{10}}}{{{x}+{1}}}}={3}{x}^{{{4}}}-{17}{x}^{{{3}}}+{3}{x}^{{{2}}}+{33}{x}+{10}\)
\(=(x+1)(x+1)(x-2)(3x+1)(x-5)\)
\(\displaystyle={\left({x}+{1}\right)}^{{{2}}}{\left({x}-{2}\right)}{\left({3}{x}+{1}\right)}{\left({x}-{5}\right)}\)
This is the factored form of the polynomial.
Step 2
and, the zeros are,
\(\displaystyle{3}{x}^{{{5}}}-{14}{x}^{{{4}}}-{14}{x}^{{{3}}}+{36}{x}^{{{2}}}+{43}{x}+{10}={0}\)
\(\displaystyle{\left({x}+{1}\right)}^{{{2}}}{\left({x}-{2}\right)}{\left({3}{x}+{1}\right)}{\left({x}-{5}\right)}={0}\)
\(x+1=0\ or\ x-2=0\ or\ 3x+1=0\ or\ x-5=0\)
\(\displaystyle{x}=-{1},{x}={2},{x}=-{\frac{{{1}}}{{{3}}}},{x}={5}\)

0
 
Best answer

expert advice

Need a better answer?
...