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asap 4u q help (1 Viewer)

amdspotter

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using crt 3-i should be another root and using those roots and long div i got another root as x^2-2x+2. i feel i went wrong somewhere if any1 could help that would be appreciated
 

icycledough

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You're right in getting x^2 - 2x + 2. So finding the discriminant, which is -4, will tell you that the quadratic has 2 complex roots. Through working out, you can complete the square and write it as x^2 - 2x + 1 + 1, or (x - 1)^2 + 1 = 0. From there, you should be able to get the last 2 roots. Thus, the initial quartic will have 4 complex roots. To double-check, you can use an online graphing calculator and the graph should look like a quadratic but with a flatter turning point.
 

amdspotter

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You're right in getting x^2 - 2x + 2. So finding the discriminant, which is -4, will tell you that the quadratic has 2 complex roots. Through working out, you can complete the square and write it as x^2 - 2x + 1 + 1, or (x - 1)^2 + 1 = 0. From there, you should be able to get the last 2 roots. Thus, the initial quartic will have 4 complex roots. To double-check, you can use an online graphing calculator and the graph should look like a quadratic but with a flatter turning point.
Thanks 👍 yep I followed those steps
 

CLUELESS14

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using crt 3-i should be another root and using those roots and long div i got another root as x^2-2x+2. i feel i went wrong somewhere if any1 could help that would be appreciated
Use a combination of sum of roots and product of roots (because you already know two of them) and you should get it like any other year 11 polynomial question. I find it more convenient than long division where it's easier to make a mistake
 

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