4 ms·
i get A(1-x+x^2) + B(x+2) = 3x-1
by pencil 16y ago
i get A(1-x+x^2) + B(x+2) = 3x-1
- RiderOfGiraffes 16y agoExcellent. + Expand B(x+2) + Expand A(1-x+x^2) What do you get? You need to play with these sorts of equations and see what happens - see what you get.
- pencil 16y agoexpand B(x+2)?? but how??
- RiderOfGiraffes 16y agoHow would you expand 3(x+2)?
- pencil 16y ago3x+6
- RiderOfGiraffes 16y agoOr, before simplifying, 3x+3.2 (using a dot for multiplication) So how do you expand B(x+2) ?
- pencil 16y agoBx+B2 ??? now it's getting funny!!!!!!!!
- RiderOfGiraffes 16y agoSo going back, you need to solve: [ A(1-x+x^2)+B(x+2) ] / [ (x+2)(1-x+x^2) ] = (3x-1) / [ (x+2)(1-x+x^2) ] As I said, the denominators are already equal, so you need to make the numerators equal. That means you need to make this: A(1-x+x^2)+B(x+2) equal to (3x-1). Expand this - you already know that the second part becomes B.x+2B - and have a look. Then think - what can you set A and B to be to make it equal to 3x-1? What if you set A to be x? What if you set B to be 2? What if you set A to be -3? What if you set B to be 2x? Try those, try more, see if you can work out how you can get 3x-1. Here's a hint: when you expand you'll get one of the terms as Ax^2. How can you get that to cancel out? Try things. Tell me what you see, tell me what you get.
- pencil 16y agoi've started out with calculus.(it;s been 30 hours now) and i'am enjoying it as i'am able to understand.so my plan is to continue this partial fraction problem when i reach integral calculus involving partial fractions and eventually laplace transforms. and you said my algebra skills sucks.well i partialy agree with you cause i wouldn't be able to solve limits and differentiate functions without a grasp on algebra(precalculus for namesake). as a matter of fact i've never been good at anything .i suck in everything that i do.!!!!!!!!!
- RiderOfGiraffes 16y agoJust to add another question - why is that funny? A and B represent polynomials - why should this be funny to you?
- pencil 16y agothe fun part has got nothing to do with polynomials.i'am finding it funny cause i'am taking ages to learn this basic concept .to put in better sentence a DUMB ASS(that's me) taking advice from a knowledgeable person(that's you) by the way thanks very much for telling me that 'A' and 'B' represents polynomials.never knew it before.
- RiderOfGiraffes 16y agoIt's not necessarily that you're dumb - I suspect you aren't. The problem is that you're trying to get a grip on these techniques when you haven't really mastered the absolute basics of algebra. It's not surprising - you're trying to teach yourself, and it's always going to be that there are gaps. You need properly constructed tutorials and exercises. Have a look at these: http://www.google.co.uk/#q=algebra+tutorial+with+exercises http://www.google.co.uk/#q=algebra+tutorial+with+exercises Pick one of the tutorials and work through it completely. Then you can do a google search for partial fraction tutorials and do the same.
- pencil 16y agoi've started out with calculus.(it;s been 30 hours now) and i'am enjoying it as i'am able to understand.so my plan is to continue this partial fraction problem when i reach integral calculus involving partial fractions and eventually laplace transforms. and you said my algebra skills sucks.well i partialy agree with you cause i wouldn't be able to solve limits and differentiate functions without a grasp on algebra(precalculus for namesake). as a matter of fact i've never been good at anything .i suck in everything that i do.!!!!!!!!! by the way i'am not offended.i'am enjoying myself with calculus.i'll get back to you if i have any doubts.if you got to say something you can.