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anonymous
 5 years ago
Determine the zeros of f(x) = x4 – x3 + 7x2 – 9x – 18.
help :))
anonymous
 5 years ago
Determine the zeros of f(x) = x4 – x3 + 7x2 – 9x – 18. help :))

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anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0find them instantly, since you are already on line, just type it in http://www.wolframalpha.com/input/?i=x4+%E2%80%93+x3+%2B+7x2+%E2%80%93+9x+%E2%80%93+18.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0how did you get tht DASHNI?

ash2326
 5 years ago
Best ResponseYou've already chosen the best response.2We'll have to substitute and check . Let's put x=1 f(1)=1+1+7+918=0 so x+1 is a factor, we'll create this factor and will find other factors f(x)=x^4x^3+7x^29x18 writing x^4 as x^3(x+1) this has added an extra x^3, so will subtract this by x^3 x^4>x^3(x+1)x^3 so creating this factor in each term f(x)=x^3(x+1)2x^2(x+1)+9x(x+1)18x18 f(x)=x^3(x+1)2x^2(x+1)+9x(x+1)18(x+1) f(x)=(x+1)(x^32x^2+9x18)

ash2326
 5 years ago
Best ResponseYou've already chosen the best response.2now we'll find factors of (x^32x^2+9x18) let's check if x=1 is a factor of this 12918 =30 not equal to zero, let's check if x=2 is a factor 88+1818=0 so x2 is a factor now we'll create this factor in each term, like done before x^2(x2)+9(x2) (x2)(x^2+9) so f(x)= (x+1)(x2) (x^2+9) so the two real roots are x=1, 2 the complex roots are \[x= \pm 3i\]

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0thank you very much:)
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