Recent content by fracs49er

Yes, there isn't much doubt now that the vector cross-product method works. I want to thank everyone who contributed to the solution and to my better understanding of great circles and velocity vectors, and especially LCKurtz for providing a solution to the problem that I could finally sink my...

Your picture certainly looks like how the velocity vector appears on my diagram (Good job!), but then those two original points were supposedly in error, and the points I later posted supposedly correct. I tried setting up the cross products as in your formula, using the updated points for 0...

Life is a continuous process of learning. So you could say I am a student of life, but I don't always have time to do my homework. I never took calculus in college so vectors and cross-products are strange sounding terms to me. Matrices I have a better understanding of, but if I don't work...

Did you see the attachment I posted? It shows the circle plane clearly, and it's not just tilted with respect to the z-axis. Actually it is rotating at a 45 degree angle to the x/y axis too, in addition to being skewed with respect to the z-axis. Your assumption is I'm a math student, but...

Thanks for following this thread. There are problems with your solution: z is positive when angle = 0 (should be negative) and with angle 120 I get a z and radius greater than one. It's a unit circle with origin at 0,0,0! So maybe you made a mistake in your solution. Note: I posted a new set...

Angle 0 is the angle in the circle, starting from the 12 o'clock position. The rest of angles 0-360 follow around the circle clockwise. The projection is actually a circle. It's only drawn as an ellipse to emphasize the angle it is tilted. The circle plane is tilted both 45 degrees from the...

I think the tilt is -45 degrees (the circle plane is first tilted back 45 degrees then to the left toward the -x axis 45 degrees) Note: the z axis is perpendicular to the x/y plane which is the plane of the page, x-axis is horizontal, y-axis is vertical, not exactly a standard orientation which...

No, the two points aren't always spaced by 90 degrees. The points are easier to calculate visually when one component is zero, that's all. I have some new (revised) points, that appear to be accurate: 0 degrees = (0x, .707y, -.707z) 30 degrees = (.354x, .354y, -.866z) 60 degrees =...

I don't have any experience working with conic sections. My college trig only covered 2D not 3D objects. What I need are formulas in the form of x=f(xt),y=f(xt),z=f(xt), where xt is the angle on the circle and f is the formula with whatever functions are needed to map the circle's orbit. It's...

Hi, I've researched this problem all across the web and most answers involve finding the distance between two points on a great circle, mostly in nautical terms, using latitude and longitude, etc. but that isn't the answer I'm looking for. It's generally agreed if you have two points on a...