Recent content by Astronomer107

  1. A

    Integration Problems

    ok... here's what I'm doing. the integral of 8x^(1/2) - x^2) by dx, boundaried 0 and 2, which is: 2/3 * 8x^(3/2) - 1/3 x^3. When I plug in the 2, I still get 120/3, which is wrong. On the Sin^-1 x problem, I stopped at sin x/ (1-cos^2 x) because I couldn't figure out how to cancel out...
  2. A

    Integration Problems

    Thanks for your help! On the 2nd one, I still got the same answer, so the book is probably wrong (it frequently is) or I still am incorrect. Thanks for reminding me that sin^2x = 1-cos^2x. I'm still working on getting an answer for that one though. For the last one, I don't know how to find the...
  3. A

    Integration Problems

    Integration Problems!! Help! I have a problem with the following: 1. Sketch the graph of the function y^2 = x^4(x+4) and find the area enclosed by the loop. -- I don't see any loop! 2. Find the area of the region enclosed by th curves y= x^2 and y^2=8x. -- The answer given in the back is...
  4. A

    Females are not dumb I just need help

    Since one male in the class thinks the two females in my IB physics class are dumb (I being one of them), we are determined to do very well on tonight's problems. We don't have a teacher that actually teaches, I don't know how to approach some of the problems. Here is goes (please help! thanks)...
  5. A

    Math Question

    Another Problem In the above problem, they want me to draw an arc with the center R with a radius of 28 and then find the length of the portion of T that will be within the range of the arc. The drawing the arc was no problem, but I don't know how to find it.
  6. A

    Math Question

    Thanks! Thank you so much! I can't believe how simple that was. I have such a huge problem when I am asked to prove things. I just never seem to find the way to do it.
  7. A

    Math Question

    I'm in IB math methods, working on a project and I can't seem to figure out what to do with this problem. A radio transmitter sends signals to a railway which run along a straight track. When a set of coodinate axes is used to represent this system, the transmitter is at R(1,0), and the track...
  8. A

    Mathematica Mathematical Proof?

    Mathematical Proof??? Can anyone tell me how to prove things mathematically? I'm not sure you can because I'm convinced that proving equations and formulas is something that you just see how to do if you are intelligent (if that is the case, then I must be stupid). I have trouble with this in...
  9. A

    Is angular momentum of the planet conserved?

    What is it meant by: mr(1)V(1)= mr(2)v(2) The quantity mrv is called the angular momentum of the planet. Is angular momentum of the planet conserved? What do they mean conserved?? Thanks and sorry such short notice... my physics teacher soooo nicely gave us 2 days notice to finish all...
  10. A

    Stupid-yet-needs-to-be-answered Question

    Hi, I'm back with another question (IB Math Methods). It's kind of easy and I don't know if I'm stupid or having a brain lapse but it is this: When finding the inverse of h(x) = (/sqrt{x-1}), x > -1, I got y = x^2 + 1, but what do I do with that x > -1 ??? THANKS!
  11. A

    IB Physics I

    oh, ok. I think I get it. The diagram shows those lines perpendicular and parallel to the slope, but I think I jsut got confused because gravity had always been the downward component that my teacher never really explained. I have a test tomorrow, so I'm hoping I don't fail. Usually he assigns...
  12. A

    IB Physics I

    Hi, I'm in IB physics and I'm having a little trouble since the teacher would rather play computer games than teach us (the book isn't great either). Right now we're working on force and I was wondering if anyone could clarify a few things for me please.I'll just work through some problems and...
  13. A

    IB Math Methods- Problems with Problems!

    I have a few problems: Solve 1. 32^2x = e e^2x +1 I cross multiplied and got 3e^2x = e(e^2x + 1) Then: 3e^2x = e^2x+e And now I don't know what to do from here.... 2. Solve e^2x - 5e+x + 6 = 0 This one can't be factored, so does the quadratic equation work here? If so...
  14. A

    Geometric Sequences and Logarithms

    I'm having trouble with these type of probles (where a negative log comes up): (All of this is solving without sigma notation) Find the number of terms in these geometric sequences and the sum of the numbers. 11, -22, 44,....,704 I know that a1 = 11, r = -2, and an = 704, so I did...