PreCalculus/Trig Check please and help
posted by Tabitha
Could someone please check the first one and help me with the second one. I'm stuckThank you
1.What are theroots of the following polynomial equation?
(x+2i)(x5)(x2i)(x+8) = 0
I think the roots are 2i,5,2i,8you take out the roots as opposites of what are in the equaion correct?
2. Write a polynomial of the smallest degree with roots 3,3i and 3i
Final answer can't have parentheses
(x3)(x3i)(x+3i)=0 and then I'm stuck I don't know what to do when you multiply the x times the 3i

Mgraph
First find (x3i)(x+3i)=x^2+9 and then
(x3)(x^2+9)=x^33x^2+9x27 
bobpursley
Do the last two first: (x3i)(x+3i) You can do FOIL (the anwer to x*(3i) is 3xi), however, notice x+9 is the answer. (x^2+9) is the difference of two squares, x and 3i, so (x^2+9)=(x+3i)*(x3i)
so you now have (x3)(x^2+9)
= x^3+9x 3x^327 Using the FOIL method. 
Tabitha
Whenn I get to (x3)(x^2+9) and FOIL wouldn't it be x^3 +9x3x^2 27? I get (3x^2) not (3x^3) when I multiply 3 times x^2 or am I missing something
Thank you 
bobpursley
correc, typo. 3x^2
Respond to this Question
Similar Questions

Precalculuscheck answers
Write the polynomial equation of least degree that has the roots: 3i, 3i, i, and i. Answer: (x+3i)(x3i)(xi)(x+i)=x^4+x^3x^3i+9x^2+9x9xi9i 2)Determine if the expression 4m^56m^8+m+3 is a polynomial in one variable. If so, state … 
PreCalc/Trig
Please helpI'm stuck really bad What are the roots of the equation x^2  4x + 3 = 0 I think I was suppose to use b^2  4ac so it would be 4  (4)*1*3 = 12 so the roots would be 12 and 12 Thank you for any help you can provide 
PreCalcPlease check my answer
Please helpI'm stuck really bad Thank you for any help you can provide What are the roots of the equation x^2 4x + 3 = 0 x^2  4x = 3 x^2 +2(2)x + 2^2 = 3 = 2^2 x^2 + 4x + 4 = 1 (x + 2)^2 = 1 qrt (x+2)^2 = sqrt 1 x+2 = plus … 
PreCalcPlease check my answerI think its correc
Could someone please check theseI had tried one last night but it was really wrong so I'm been workinghopefully these are correct. What are the roots of the equation and answers have to be simplified 2x^2 + 5x10 =0 2x^2 + 5x10+10=0+10 … 
PreCalcPlease check my answerI think I have it
Could someone please check theseI had tried one last night but it was really wrong so I'm been workinghopefully these are correct. What are the roots of the equation and answers have to be simplified 2x^2 + 5x10 =0 2x^2 + 5x10+10=0+10 … 
PreCalcPlease check my answerI think I have it
Could someone please check theseI had tried one last night but it was really wrong so I'm been workinghopefully these are correct. What are the roots of the equation and answers have to be simplified 2x^2 + 5x10 =0 2x^2 + 5x10+10=0+10 … 
PreCalc/Trig
Please check the first and help with the secondthank you Find all possible rational roots of f(x) = 2x^4  5x^3 + 8x^2 + 4x+7 1.I took the constant which is 7 and the leading coefficient which is 2 and factored them 7 factored would … 
calculuscan someone please help me with this ques
Find all zeros of the following polynomial. Write the polynomial in factored form. f(x)=x^33x^2+16x48 I put: x^2(x3)+16(x=3) (x3)(x^2+16) For zeros: x3=0 x=0 **My teacher stated check the equation solution again. What is the value … 
Math check my answers
I posted this before can someone please check my answers and help me thanks:) 2 rectangles have equal areas determine the area of each rectangle then use this info to determine the perimeter. rectangle one: length of 2p + 3 width of … 
Math
If one root of the equation x^2px+20=0 is 4,while the equation x^2qx+p has equal roots, then possible value of q is. A)3. B)4. C)5. D)6. I think 6 is correct. Please check it.