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Mathematics 13 Online
OpenStudy (driftracer305):

write a polynomial function with given roots :- 3+i , 2 and -4

OpenStudy (imstuck):

This will be a fourth degree polynomial. One root is (x - 2), another is (x + 4) another is (x - (3 + i)) and because you have a - (3 + i), you also have to have a + (3 + i).

OpenStudy (imstuck):

So here they are, all in a row!

OpenStudy (driftracer305):

ok

OpenStudy (imstuck):

(x - 2)(x + 4)(x - [3 + i])(x + [3 + i])

OpenStudy (anonymous):

if \(a+bi\) is a root, so is \(a-bi\)

OpenStudy (anonymous):

Otherwise, the function would not have real coefficients

OpenStudy (anonymous):

Unless this is supposed to be a complex polynomial

OpenStudy (driftracer305):

ahh.........i get it

OpenStudy (imstuck):

So let's multiply those out, 2 sets of parenthesis at a time. Let's work with the first 2, becasue they do not have the imaginary i in them.

OpenStudy (driftracer305):

uhh wait

OpenStudy (imstuck):

(x - 2)(x + 4) =\[x ^{2}+2x-8\]

OpenStudy (driftracer305):

x^2+2x-8

OpenStudy (driftracer305):

ok gotcha......next thing?

OpenStudy (imstuck):

wait for what? O right! That's right, you got it! Now let'ss do the others.

OpenStudy (imstuck):

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