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toadytica305
Group Title
List all the real and imaginary zeros of
f(x) = x^3+x^2+ 13x  15... 1 is a zero of the function
 2 years ago
 2 years ago
toadytica305 Group Title
List all the real and imaginary zeros of f(x) = x^3+x^2+ 13x  15... 1 is a zero of the function
 2 years ago
 2 years ago

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satellite73 Group TitleBest ResponseYou've already chosen the best response.1
did you factor? you already knew 1 was a zero, from the last question
 2 years ago

Callisto Group TitleBest 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?
 2 years ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.1
once you factor, you find the other zeros using the quadratic formula
 2 years ago

toadytica305 Group TitleBest ResponseYou've already chosen the best response.0
You said (x−1)(x^2+2x+15) This gives zeros of 1, 3, 5, 15?
 2 years ago

Callisto Group TitleBest 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!~
 2 years ago

Callisto Group TitleBest 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
 2 years ago

toadytica305 Group TitleBest ResponseYou've already chosen the best response.0
i get \[(4\sqrt{15}) /2\]
 2 years ago

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

toadytica305 Group TitleBest ResponseYou've already chosen the best response.0
2i√14?
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.2
Nope.. \[x=\frac{2\pm \sqrt {56}}{2} = \frac{2\pm 2\sqrt {14}}{2} = 1 \pm 14i\]
 2 years ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.1
\[\sqrt{14}i\]
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.2
Sorry :S \[1\pm \sqrt{14}i\]
 2 years ago

toadytica305 Group TitleBest ResponseYou've already chosen the best response.0
Im still not sure how I get the real and imaginary zeros off that...
 2 years ago

Callisto Group TitleBest 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..
 2 years ago

toadytica305 Group TitleBest ResponseYou've already chosen the best response.0
Thankssss!
 2 years ago

Callisto Group TitleBest ResponseYou've already chosen the best response.2
Welcome!!~~~
 2 years ago
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