Write a polynomial function of minimum degree with real coefficients whose zeros include those listed. Write the polynomial in standard form.
3, -13, and 5 + 4i

Question

Write a polynomial function of minimum degree with real coefficients whose zeros include those listed. Write the polynomial in standard form.
3, -13, and 5 + 4i

anonymous · Answer

two factors you get right away 
$$(x-3)(x+13)$$

anonymous · Answer

the real question is, what quadratic has zeros $5+4i,5-4i$

anonymous · Answer

exactly

anonymous · Answer

there are three ways to fiind it 
one is long an annoying 
one is pretty easy
one is real real easy
which do you choose?

anonymous · Answer

really really easy haha

anonymous · Answer

ok but as usual there is a  trade off
the real real easy way requires memorizing something
that is, that the quadratic with zeros of $a\pm bi$ is $$\huge x^2-2ax+(a^2+b^2)$$

anonymous · Answer

you have $5+4i$ so it is 
$$x^2-2\times 5x+4^2+5^2$$ or 
$$x^2-10x+41$$

anonymous · Answer

Wow that simplified it thank you

anonymous · Answer

wait but is a=5 or b=5