Recent content by imsoconfused

here is the one wikipedia gives, I have changed it around some (essentially just changed the constants) to obtain different looking shells: http://en.wikipedia.org/wiki/Seashell_surface be sure you set it 1:1, otherwise it looks too fat.

I've been doing some experimentation with plotting parametrized surfaces in maple, and I would like to get some ideas for more things I could do. I'm not very clever at figuring out new parametrizations, but I'd like to do some things with seashells. The plots I'm coming up with are very...

dA/dy=12-6y. y=2, and then (12-3(2))*2=12 and that's the area. I knew it couldn't be that hard. thanks!

Homework Statement A rectangle has sides on the x and y axes and a corner on the plane x+3y=12. Find its maximum area. Homework Equations A=xy=(12-3y)y (A=12, according to the solution manual.) The Attempt at a Solution At first I thought the corner it was talking about lay...

ok. so if I were to draw this thing, it would basically look like a flat plane with a hump in it near the origin? that's what brought on this question; I'm supposed to be drawing it.

oh, I know it shouldn't be that hard, but I really appreciate your coaching me through this. just think where I'd be without you!

when x and y grow larger, z approaches 1. that is why I thought it looked like (1/x)^2, because that decreases exponentially towards an asymptote. the difference is that this, instead of being a line is a surface. correct?

oh wait, I just need to choose a z and use logarithms to find y in terms of x. correct?

and now comes the inane question about how to plot some points. just pick random x's and y's?

ok, I see how you get z=2, at least. I feel so stupid in that I only get about half of the second part and I absolutely cannot see what this thing looks like! I'm thinking of z as a level--is that wrong? looking at this from the xy plane, does it look like a function like (1/x)^2? I have...

I can't quite see it yet. why wouldn't you just let r=-x^2-y^2?

I don't understand what you mean by cylindrical coordinates, I've never heard that term. I have trouble picturing things, too, until I start plotting points. Is that what I should do, just begin plotting points until I start to see it?

sorry, yes. and I made a typo--it's z= 1+ e^(-x^2-y^2).

Is 1 + e^(-x^2+y^2) a two-sheeted hyperboloid? thanks

1. The period of the Earth's orbit is approximately 365.25 days. Use this fact and Kepler's Third Law to find the length of the major (not semi-major) axis of the Earth's orbit. You will need the mass of the sun, M = 1.99x10^30 kg, and the gravitational constant, G = 6.67x10^-11 Nm^2/kg^2...