Complete the square - Help please :)
Not to good with fractions, so I'm posting this here.
x^2 + 3x +4
Complete the square.
Ill try:
(x + 3/6)^2 + ?
lol best i can do sorry :)
Thanks
x^3 +bx^2 -2x^2 -2bx +xc -2c
got this down to:
x^3 +(b -2)x^2 + (c -2b)x -2c
so i get:
2c = +4
-3 = b-2
Agree?
If I'm correct my confidance will go up lol!
K thanks,
I have another problem lol!
This is the full thing along with where i have got to so far:
Find Factors For:
f(x) = x^3 -3x^2 + 4
soon that was down to:
x^3 -3x^2 + 4 = (x -2) (x^2 + bx + c)
then simplyfied/factories down to:
x^3 -3x^2 +4 = x^3 + (b-2)x^2 +...
if x^2 X -a/x^2 = a
then how did my tutor get
-a/x^2 X a/x^2 = -a^2/x^4 ?
Wouldnt it be the same rule meaning -a/x^2 X -a/x^2 = +a^2
I got +a^2/x^4
i guess it wouldn't as its both DIVIDED BY x^2 rather than
x^2 X a/x^2
Hmm, clearly need to revise this but can't find...
yeh i definatly have. Know any websites which have good explanation of this stuff?
I need to revise it before continuing and I am really far behind in my studys! at this rate ill of read everything once and will have 0 Revision time :(
Do you have a webpage or any ebooks with this...
which minus sign errors?
when i try this i end up getting:
x^4 -2a/x^8 -a^2/x^4
Must have gone wrong with the +/- somewhere because my tutor has 2a over nothing.
But i have 2a/x^8.
So when simplifying i assume i should of had -a/-x^4 and -a/+x^4 therefore cancelling each other...
but i need to know how to get there lol :)
anyone got good website with expanations on / In expanding!
I have never seen Divisions in () ()'s
So need to get my head around them
thanks
yeh i did it like that but it got sooooo messy and screwed up!
I mean what does: x^2 multiplyed a/x^2 =?
ax^2/x^4?
or
ax/x^4
Really confused lol! Need to learn this expanding stuff with / involved!
never done them much before and when i did, i got them all wrong
Please post...
Definatly need to practice... this has puzzled me!
(x^2 - a/x^2) (x^2 - a/x^2)
I know the answer is:
http://img91.exs.cx/img91/8392/x2.jpg
Problem is when i tried it...
i got it all wrong!
i normally use the high school "FOIL" technique...
But i can't use it on that!
I...
Thank zurtex, that's made me realize i REALLY REALLY need to touch up on my expanding/Factoring alot!
Got three basic rules now:
Collect like terms
Factorise where possible
Look at it again and follow the above steps :P
Ok I'm off to relearn factorising and expanding as i have clearly...
That kind of helps and i also saw the book get (1 - a) from ax^2 etc. etc.
How did you get that? Are you simply expanding it so that you have a number to work with and because there is no coefficient for A it must be 1?
(Note: I am talking about the +(1 - c)x^2 )
Also, Expanding...
"olving the square" ones. And others such as
x^3 + ax^2 -3x + b =(the three line = Symbol) (x -c)(x - 4) (x+ 5)
i understand the way to solve some using the "values" method.
But the "coefficents" or "Comparing coefficents" method is confusing.
Hey guys,
Having trouble gettign my head around these indentities!
So confusing so does anyone have a website which goes through the explanations systematically.
My textbooks touches on it but the explanation doesn't cover all the variations.
and the "letts AS Revisions guide"...