factorising

  1. D

    Factorising an expression?

    Sometimes I think that just a little discussion can make all the difference if like minded people can help each other out(Happy) I am asked to factorise the following expression; 6p^3 - 4pq + 2p. This I understand to be reverse engineering, but I seem to struggle with it at the moment...
  2. G

    Factorising polynomial over complex numbers

    The question: Factorise the polynomial z^4 + 2z^2 - 3 over the complex numbers. My attempt: Let u = z^2 u^2 + 2u -3 = 0 \frac{-2 \pm \sqrt{4 - 4(1)(-3)}}{2} u = 1, -3 (u - 1)(u + 3) = 0 (z^2 - 1)(z^2 + 3) = 0 What do I do from here? Do I take z^2 = 1 (for example) then apply De'Movres...
  3. B

    Factorising another polynomial over C

    Hi there I have a start on this polynomial: f(z) = x^4 - 2z^2 - 16z - 15 If I let f(z) = f(-1) I will find that the expression equals zero and so (z+1) is a factor. But where do I go from here? The answer in the back of the book is (z+1)(z+1+2i)(z+1-2i)(z-3) cheers David.
  4. B

    Factorising this polynomial over C

    Hi there I'm having trouble getting this problem out. I have to factorise this over c. 4z^2 - 4z + 17 My answer is: z^2 - z + \frac{17}{4} (z^2 - z + \frac{1}{4}) + \frac{17}{4} - \frac{1}{4} (z - \frac{1}{2})^2 + \frac{16}{4} (z - \frac{1}{2})^2 + 4 (z - \frac{1}{2})^2 - (2i)^2...
  5. S

    Confused by Factorising, perculiar answers

    I have an exam tomorrow and have just spotted a flaw in my brain. I am using a revision book with all the answers. 3 questions: This is what I'm confused about. x/p = p+c so x=p^2+pc But WHERE did the extra p come from. Surely thers only 1 p why is there now two? My...
  6. K

    factorising complex numbers

    factorise the following over C given (z-i) is a linear factor, z^3 + (1-i)z^2 + (1-i)z - i
  7. A

    Factorising a quadratic

    I need help with factorising the following: a) (c+d)^2 - d^2 I got c^2 + 2cd + d^2 - d^2 which is equal to c^2 + 2cd, is this correct please? b) 2w^2 + w - 3 How do you do this again please (need simple and clear advice)? Thanks
  8. Y

    Factorising quadratic equations

    Hi I have a question in my maths textbook that I can't figure out. It goes like this: Please, I'll be really grateful if someone could take the time to show me the workings of this sum.
  9. A

    Factorising a quadratic

    Could someone explain to me as simply as possible how to factorise 2x^2 + x - 3 I know the answer is (2x + 3) (x - 1) from my textbook but I don't understand the method used.
  10. A

    Factorising algebraic expressions

    This is what I have done so far but feel it might be wrong. Factorise the following: 1) Xsquared - Ysquared = (X - Y) (X + Y) 2) (C + D)squared - Dsquared = C (C + 2D) 3) 2Wsquared + W - 3 = how do you do this one again?
  11. A

    factorising a polynom with it's roots

    The polynom $A= (a-b)x^4+(c+d)x^3+(e-f)x^2+(g+h)x$ has the roots 0 and the roots of unity, so A is a multiplicity of $x(x^3-1)$. That means $c+d=0, e-f=0$. And one can say 4a-b=1$ and $g+h=-1$ without loss of generality. My question ist: why it is true only with w.l.o.g ?
  12. A

    factorising? (not sure)

    hi, this is my question: solve 2+3x+5(x-1)=7X-1? would i do: 2+3x+5x-5=7x-1 8x-3=7x-1 x-3=-1 x=2?? if i am wrong could you please let me know where i have gone wrong! and if im right could you also let my know if its right! Thanks!
  13. A

    factorising

    hi this is my question, i need to factorise this: x^2 - 81? im having a few problems with factorising at the moment so could someone let me know how to work this out! would i be correct if i did this (x^2 - 81)??(Worried) Thanks
  14. G

    Help factorising these please :(

    1) y=1/4x^4-3/2x^2+2x 2) y=1/4x^4+1/3x^3-x^2 3) y=x^3+x^2-x Thanks a lot :) EDIT: nvm- figured it.
  15. G

    Another factorising question.

    OK one more problem I have 6(2x+y)^2-26x-13y+6 There are several ones like these i need to do but I should be able to do those if I can tackle this one. I have no clue where to start with this one.
  16. Mukilab

    factorising indices

    Am I right in saying you cannot factorise the expression x^n+1 where n if greater or equal to 3 is odd? apart from x^3 which would be (x+1)(x^2-x+1)
  17. L

    factorising

    hey, i'm finding it difficult how to factorise this equation: t³ - 3t² + 4 = 0 i've found out the answer already, but i really dont understand how i would get the answer- It would be very helpful if someone could give me a step to step guide on how to get to the answer. lolz..i've used...
  18. Z

    Factorising Imaginary numbers

    I am having trouble finding the poles z1 and z2 of f defined: f(z)=\frac{1}{2z^{2}+(6-4i)z-12i} Im pretty sure I have to factorise the denominator, but I keep getting the wrong answer which includes imaginary numbers, is it supposed to?
  19. E

    Factorising a cubic.

    Hi I have a question about algebra for example 8t^3 - 27 how to convert to this model (2t - 3)(4t^2 + 6t + 9)
  20. P

    Simplifying and factorising

    1)Simplify \frac{1}{2-11x+12x^2}-\frac{1}{12x^2-5x-2} 2)Factorise 49x^2-64(y-x)^2 For the first question, My attempt is: \frac{12x^2-5x-2-2+11x-12x^2}{(2-11x+12x^2)(12x^2-5x-2)} =\frac{6x-4}{(2-11x+12x^2)(12x^2-5x-2)} I am confused at deciding on how to start the second question....