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kingjewel1

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Everything posted by kingjewel1

  1. Lovely!! How do you come about the formula to use? I'm still not sure how to find c.
  2. Ahhh my fault! sorry wrote the wrong function. y=x+1 excuse me
  3. The functions only intersect twice.
  4. But i can't factorise because i don't know where it cuts the x axis. Maybe this helps: the curve passes through where y=6/x and y=x+1meet. I set them equal that's where i found the points A and B. Edit function is y=x+1
  5. ax^2+b^x+c is the standard function of a quadratic. If i know that a quadratic with this format passes though points A(-3,-2) and B(2,3). How would i go about working out a, b and c? This's got me stumped. Thanks
  6. I take your point "The Rebel". I actually have the functions drawn out infront of me to make sure they do intersect where i thought. Like this: functions <click>. I calculated the area in two stages in the end. Thanks guys for all your help
  7. yeah sure you could do that. it's just that i wanted to do it all in one go by joining the functions. just like eg area between x^3 and x^2 in the positive quadrant X= 0 and 1 intx^3-x^2dx betweent 0 and 1 =x^4/4-x^3/3 sub in 1 = 1/12 Just the same as doing intx^3dx - intx^2dx between 0 and 1 why doesn't this method work for the other functions? this is buggin me
  8. i have examples where i've equalled two intersecting functions and then integrated the result... i'll see if i can dig some out. I was wanting to find the total area bounded by the quartic and the quadratic. I integrated between 0 and 0.9 because x=0.9 is where the two functions intersect in the positive quadrant. somebody mentioned integrating with respect to y but then i'm not sure how to do that. making y the subject from this guy or would i not just need to int(1/(1/x^4-x^4)) . y=1/x^4-x^4-x^2 how do i make y subject here? excuse my ignorance
  9. you see, i've been setting the functions equal to each other thus 1/x^4-x^4=x^2 and integrating this with respect to x between 0 and 0.9 which is it's positive intersecting point. why can't i do this?
  10. i'm trying to work out the area between 1/x^4-x^4 and x^2 and the x axis and the y axis 1/x^4-x^4 and x^2 can you give me a hand please? i've integrated between 0 and 0.9 but it gives me a negative area. :S what am i doing wrong? eventually i wanted to work out the area between -x^2 and the quartic. -x^2 aren't these curves beautiful
  11. thanks. i could see the -1 as being factor but i thought there might be a way to figure out the other one(s): relatively easily i've looked on the net but i don't seem to be coming up with any answer. :S
  12. how do i solve this guy? thanks
  13. how do i work out that if a machine is worth $15000 and if it's price decreases by 20% per annum that it will cost $9600 in two years using Sn=a(r^n-1)/r-1? using this formula it doesn't work.... thanks guys
  14. 1.a potential problem with human cloning is when the technology falls into say... bin laden's hands and he makes a super human race. 2. religious ethics say that God created every living cell: cloning goes against that grain for some people. 3.what's the point of human cloning? "there are enough of us as it is": say others 4.clones could become dispensible: where they are just used for a purpose and then disgarded. pick a reason
  15. kingjewel1

    1and1

    When does 1 and 1 make 3? Happy New Year
  16. LOL yup my examiners appear to have certain retention so..... the problem is that i've seen all three answers from 3 different sources. i mean you might aswell use the right answer if that's what they're looking for... would c) be good enough though?
  17. how do i know when to incorporate the Kw constant into the calculation of the pH of an acid? eg. i have 1x10^-8 mol dm^-3 HNO3. a ridiculously small amount of acid in water... this means that the H30+ from the dissociation of the water actually is greater than this acid: 1x10^-7. my question is how do i know not to incorporate it into an strong acid equation.
  18. hi there, i was hopeful someone could clear this up for me. if i have a solution of H2SO4(aq) and i want to calculate its pH would i count the deprotonations of both H+ ions as equal? eg. if the concentration of my solution is 0.3mol dm-3 what is my pH? is it? a) -lg2[0.3]=0.22 or b) -lg[0.3]=0.52 the thing is the 2 proton is obscured by the first so to say. in a way 1:10 concentration. so... would it be... c) -lg[0.33]=0.48? i like the last one but i've seen both the first two before tell us what you think thanks
  19. at 1000K the equilibrium constant for H20(g)+C(s)<=>H2(g)+CO(g) is 3.72atm. If total pressure is 25atm what would the partial pressures be? Could someone tell me if i've got the right answer in: 69% reacted. therefore Partial pressures (Pg): Pg(H20)=3.875 Pg(H2)=8.625 Pg(CO)=8.625 i used x=reacted H20 1-x ; C 1 ; H2 x; CO x; total=3 Xg= 1-x/2; unity; x/2; x/2; for the compounds respectively. i'm not sure how to treat carbon as it is solid. do i count it as 1 when calculating the equilibrium total moles? thanks in advance. my Alevel is in a week n i'm not sure of this one
  20. hi there. would you mind helping me a lil with this one. it's sinx=1/2+cosx i think its really easy to solve but i can never get a positive value for it. i tried substituting Cos2x=1-2sin^2x also tried it it with sec^2x=1+tan^2x i know there's 1 positive and 1 negative value at least. between 0 and 2pi thanks in advance
  21. if you think of a circle as a polygon with infinite sides, it will have infinite triangles-2. so if you use the formula to calculate the are of a triangle n n=number of sides A=1/2abSIN© you can substitute C for (n-2)pi/n if you then multiply the area of 1 triangle by infinity-2 you will have pi or close enough. try it out with 99999 sides
  22. Hi there, i see pi as being the area of a circle with radius 1unit. considering a circle is a equilateral polygon with infinite sides: ergo area of polygon= (∞-2).1/2.sin(∞-2).pi/∞ As has been stated only the boundaries can be worked out see if it helps **Happy Holidays Guys!!
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