Math Is Fun Forum
You are not logged in.
- Topics: Active | Unanswered
#1 Re: Help Me ! » Triple Integration » 2010-12-14 18:01:58
Hey Bobbym, can you please elaborate on what you are doing? It sounds interesting 
#2 Re: Help Me ! » Triple Integration » 2010-12-14 05:23:19
Thanks for the post Jane, I'll look into it!!
But I've managed to solve the problem with triple integrals
#3 Help Me ! » Triple Integration » 2010-12-12 15:25:58
- ilovealgebra
- Replies: 5
Ok, so I'm required to set up and solve an iterated triple integral so find the volume of the solid G that is enclosed by the plane z=y, the xy-plane and the parabolic cylinder y=1-x^2.
How on earth do you find these limits! If It's possible could someone give an analytic approach opposed to a geometric one. I find that once I can do things analytically then I find it easy to learn the geometric way! (if this makes sense at all 
)
Cheers in advance all
#4 Re: Help Me ! » Integration in polar coordinates » 2010-12-02 14:21:39
Oh my God facepalm!!! For some reason I thought
Ahh cra.p sorry guys epic fail there!!
Sorry to waste your time guys! argh!
#5 Help Me ! » Integration in polar coordinates » 2010-12-01 14:51:35
- ilovealgebra
- Replies: 5
Hi I am required to find the following iterated integral by converting to polar coordinates
This is what I've done so far...
Now what do I do?? Can you simplify the integral to...
Or is there some other neat way of doing it?
Cheers guys!!
#6 Re: Help Me ! » Double Integral in Polar Coords » 2010-11-23 19:30:54
Haha I'll try my best=)
#7 Re: Help Me ! » Double Integral in Polar Coords » 2010-11-23 17:25:02
Yeah all good, just working my way through chapter 15.3 then will be moving onto 15.5 & 15.7
#8 Re: Help Me ! » Double Integral in Polar Coords » 2010-11-23 13:36:48
Ahh well when i differentiate
I end up getting
So yeah, I forgot to divide by the coefficient of theta, which was 2 in this case.
#9 Help Me ! » Double Integral in Polar Coords » 2010-11-23 01:18:44
- ilovealgebra
- Replies: 7
Use a double integral in polar coordinates to find the area of the region enclosed by the rose
My working is as follows:
However I don't think this is correct since it seems to be the same area as the circle with r=1. Can someone please tell me where I've gone wrong? (Also Anton says It's wrong 
)
Cheers for the help!
#10 Re: Help Me ! » Multivariable Differentiation » 2010-11-22 19:14:01
Yeah It's a beast of a question but managed to get it out after seeing the working for computing for dz/dx
#11 Re: Help Me ! » Multivariable Differentiation » 2010-11-22 00:00:06
The full question: Show that the function
satisfies Laplace's equation
Then make the substitution
and show that the resulting function r and theta satisfies the polar form of Laplace's equation
#12 Re: Help Me ! » Multivariable Differentiation » 2010-11-21 13:34:43
Thanks everyone for your replies, I can now do the rest of the question
#13 Help Me ! » Multivariable Differentiation » 2010-11-19 13:39:00
- ilovealgebra
- Replies: 10
Hi can someone please show full working on how to get the first derivative(with respect to x) of Z=arctan(2xy/(x^2-y^2)) Thanks!! By the way this is to help me solve question 60 of chapter 14.5 in Anton Calculus 7th edition (can refer to this if you have it) Cheers guys/gals!
#14 Help Me ! » Vector-Valued Functions » 2010-02-15 23:13:16
- ilovealgebra
- Replies: 1
Hey guys just a quick question.
Suppose that r(t) = (kcos(wt), ksin(wt))
Is the position vector of a particle rotating around the origin in a circle of radius k and angular velocity w.
Show that the acceleration of the particle is directed at the origin , with magnitude v^2/k, where v is the
speed of the particle
Can someone please go through this, thanks for the help
#15 Re: Help Me ! » multi var. calc » 2009-11-24 18:08:53
ok excellent, cheers for the help, also what level of education do u have atm? just curious
#16 Re: Help Me ! » multi var. calc » 2009-11-24 15:23:34
Ah ok, so final answer would then be: dz/dt = (1/2)sinh(te^t)[e^t + te^t] ?
#17 Re: Help Me ! » multi var. calc » 2009-11-24 09:45:29
that was x = (t/2)
#18 Help Me ! » multi var. calc » 2009-11-24 09:44:06
- ilovealgebra
- Replies: 6
Just a quick problem... My solution was 0, just making sure this is correct
z=(cosh(xy))^2 ; x=(t/2) , y=e^t Find dz=dt
#19 Re: Help Me ! » Logic (easy) » 2009-11-22 10:44:49
Thanks for the reply
Also, would that make ¬(B ∨ D) equivalent to (¬B ∧ ¬D)
#20 Help Me ! » Logic (easy) » 2009-11-22 10:33:01
- ilovealgebra
- Replies: 3
Hey guys.
A for Min is at home
B for Min is on board
C for Henry is at home, and
D for Henry is on board.
For...
(iii) Either both Min is on board and Henry is on board or neither is on board.
I was wondering whether (B ∧ D) ∨ (¬B ∧ ¬D) [ model answer ] is the same as (B ∧ D) ∨ ¬(B ∧ D) [my answer]
This may be really obvious but i'm just making sure cheers for the help guys
#21 Re: Help Me ! » calculus » 2009-09-14 23:43:19
Woops, was trying to figure latex and accidently pressed enter, sorry
#22 Re: Help Me ! » calculus » 2009-09-14 23:41:57
[math]\pi(n) = \sum_{m=2}{n}
math]
#23 Help Me ! » calculus » 2009-09-11 10:03:21
- ilovealgebra
- Replies: 6
A parabola is given by y^2=4ax and the ellipse (x^2)/a^2 + (y^2)/b^2 = 1 where a>0 and b>0, meet at the points P and Q.
(a) The two curves intersect in such a way that the tangent to the parabola at P is perpendicular to the tangent tothe ellipse at P.
(i) Show that B^2 = 2a^2
(ii) Hence, find in terms of a, the distance of the point P from the origin O.
(b) The tangent to the parabola at P meets the x-axis at M. The tangent to the ellipse at P meets the x-axis at N. Show that the length of MN=(2*(sqrt)(2))a.
Hi guys, I have solved (a), but am having problems with (b) I was wondering if anyone can show a full solution using a parametric method. i.e. using (at^2,2at) for the parabola and dy/dx=(1/t) if that helps. Cheers
#24 Help Me ! » Implicit Differentiation » 2009-05-02 16:40:37
- ilovealgebra
- Replies: 2
OK having problems with this one: Find the gradient of the normal to the curve 2xy ² -x²y³ =1 at the point (1,1)
Thanks in advance!
#25 Re: Help Me ! » Trig » 2009-04-28 21:35:04
Thank you!