Recent content by nirvana1990

Aahh it says I wrote that reply up there! Anyway thanks for the help- so the only reason we do that is so that we are able to compare the coefficients? I don't think I'll look for the proof online! Maybe I'll just move on to the next chapter... Thanks again!

Thanks for the reply. When we're splitting up the fraction into partial fractions why do we then split up the denominator like this: A/(z-8)+B/(z-8)^2+C/(z-8)^3? Why do we not do : A/(z-8)+B/(z-8)+c/(z-8)? Add them! That's just (A+B+C)/(z-8) and since A, B, C are just some constants...

Homework Statement I don't understand something I have read about partial fractions so I wonder if anyone can help! To each repeated linear factor in the denominator of the form (x-a)^2, there correspond partial fractions of the form : A/(x-a) + B/(x-a)^2 Is this true if we have...

Sorry this is all rubbish! I didn't even have a benzene ring but I'm able to name what I did have!

Homework Statement There's a benzene ring with both OH and H attatched to the same carbon atom on the benzene ring and I was wondering what this molecule would be called. The Attempt at a Solution I thought it might be an acid group attached to the benzene ring but wouldn't there...

Woah that's so cool! Well not "cool" but you know... Thanks for the explanations!

So I can't really give just one value for a and one value for b? The back of the book says a=3,b=-12 but is this just one set of solutions? Thanks for the replies!

Homework Statement Once again I'm stuck... Find a and b if x^4+ax^3-2x^2+bx-8 is divisible by x^2-4. The Attempt at a Solution x can be + or - 2 so P(2)=0 and P(-2)=0 P(2)=8a+2b=0 P(-2)=-8a-2b=0 I don't think I can solve these simultaneously since everything will cancel so how...

Oh yes thanks! x^2/a^2+y^2/b^2=4t^2+1-2t^2+t^4/1+2t^2+t^4 So the left hand side cancels to give 1. Thanks again!

Homework Statement If x=2at/(1+t^2) and y=b(1-t^2)/(1+t^2), show that x^2/a^2+y^2/b^2=1 The Attempt at a Solution I've tried squaring both equations: xt^2=4a^2t^2/(1+2t^2+t^4) y^2=b^2(1-2t^2t^4)/(1+2t^2+t^4) Now I've tried adding x^2 and y^2...

Oh yay I get it now! Thank you sooo much!

Thanks for the help! I've rearranged the 2nd eq. ad divided by 2 to get (like you say) 3/2(x+y)=2xy but I don't understand how this has gone into the 1st eq. and what we're substituting it for?

Oh ok so using what dynamicsolo says I got: 1/y=(4x-3)/3x Taking the reciprocal I get: y=3x/(4x-3) Sub this in eq.1: x^2+9x^2/(4x^2-24x+9)=10 is this right so far? Can I then multiply up to get a quartic equation and (somehow) solve that?! Thanks for the help!

Thanks for the reply! I've now rearranged the 2nd eq. : 1/x=4/3-1/y and I've inversed it all to get: x=-3/(3y-4), I then substituted this into the 1st eq. and rearranged to get: 9y^4-24y^3-74y^2+240y-151=0 is this right??

[SOLVED] Simultaneous equations Homework Statement Solve: x^2+y^2=10 and 1/x+1/y=4/3 Homework Equations er... I've tred substituting y=mx into eliminate y The Attempt at a Solution I tried squaring the2nd equation to give: 1/x^2+1/y^2+2/xy=16/9 Then I substituted...