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Cphill Thank You, I told my friends I will marry you one day. xD. Heres another one... 

 

Write a polynomial function in standard form that has zeros 3 and 2i (Hint: Are there other zeros?). Thank you, and will you please add in the steps? They help ALOT.

 May 19, 2016
 #1
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If 2i is a root.....so is its conjugate,  - 2i.....so......the polynomial, P(x),  is

 

P(x)   = (x - 2i) (x + 2i)(x -3)      simplify  the first part

 

(x - 2i)(x + 2i) =     x^2 - 4i^2    note....  [i^2 =  -1]  .........so we have, for this part

 

x^2 - (4)(-1)  =

 

x^2  + 4     .......now......multiply this by the other factor, (x -3), and we get

 

(x^2 + 4) (x - 3)   =

 

x^3 - 3x^2 + 4x - 12       and that's the polynomial, P(x)

 

This will verify the results : 

http://www.wolframalpha.com/input/?i=x^3+-+3x^2+%2B+4x+-+12++%3D+0

 

 

 

cool cool cool

 May 19, 2016

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