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List all the real and imaginary zeros of
f(x) = x^3+x^2+ 13x  15... 1 is a zero of the function
 one year ago
 one year ago
List all the real and imaginary zeros of f(x) = x^3+x^2+ 13x  15... 1 is a zero of the function
 one year ago
 one year ago

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satellite73Best ResponseYou've already chosen the best response.1
did you factor? you already knew 1 was a zero, from the last question
 one year ago

CallistoBest ResponseYou've already chosen the best response.2
I think the question asks to solve f(x) =0 Since the question gives you 1 is a zero of the function. (x1) is a factor. Now, do the division to get the other factor first, can you?
 one year ago

satellite73Best ResponseYou've already chosen the best response.1
once you factor, you find the other zeros using the quadratic formula
 one year ago

toadytica305Best ResponseYou've already chosen the best response.0
You said (x−1)(x^2+2x+15) This gives zeros of 1, 3, 5, 15?
 one year ago

CallistoBest ResponseYou've already chosen the best response.2
Nope!~ f(x) =0 x^3+x^2+ 13x  15 =0 (x−1)(x^2+2x+15) =0 So, x1 =0 (1) or (x^2+2x+15) =0 (2) You can solve (1) easily. And solve (2) using quadratic formula!~
 one year ago

CallistoBest ResponseYou've already chosen the best response.2
For a quadratic equation ax^2 + bx + c=0 \[x=\frac{b \pm \sqrt{b^2  4ac}}{2a}\]^ Quadratic formula
 one year ago

toadytica305Best ResponseYou've already chosen the best response.0
i get \[(4\sqrt{15}) /2\]
 one year ago

CallistoBest ResponseYou've already chosen the best response.2
It doesn't seems right... \[x=\frac{2 \pm \sqrt{2^2  4(1)(15)}}{2(1)} =?\]
 one year ago

CallistoBest ResponseYou've already chosen the best response.2
Nope.. \[x=\frac{2\pm \sqrt {56}}{2} = \frac{2\pm 2\sqrt {14}}{2} = 1 \pm 14i\]
 one year ago

CallistoBest ResponseYou've already chosen the best response.2
Sorry :S \[1\pm \sqrt{14}i\]
 one year ago

toadytica305Best ResponseYou've already chosen the best response.0
Im still not sure how I get the real and imaginary zeros off that...
 one year ago

CallistoBest ResponseYou've already chosen the best response.2
the real one is 1 the imaginary ones are \[1\pm \sqrt{14}i\] Actually, the question just asks to you to solve f(x) =0 ... I think..
 one year ago
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