Geometry refresher

[gwynhefar]

Because I am torturing myself by reading Newton, y'all get to relearn geometry with me. Here are some terms I had to look up again to make sure I understood exactly what they meant:

parabola: (n) A symmetrical open plane curve formed by the intersection of a cone with a plane parallel to its side; the curve traced by a point whose distance from a given point (the focus) is equal to its distance from a given straight line (the directrix); a curve that is the graph of an equation of the type y2 = 2px, or y = ax2, where p and a are constants.

hyperbola: (n) One of the conic sections; a plane curve consisting of two separate, equal and similar, infinite branches, formed by the intersection of a plane with both branches of a double cone (i.e. two similar cones on opposite sides of the same vertex). It may also be defined as a curve in which the focal distance of any point bears to its distance from the directrix a constant ratio greater than unity. It has two foci, one for each branch, and two asymptotes, which intersect in the centre of the curve, midway between the vertices of its two branches.

vertex: (n) The point opposite to the base of a (plane or solid) figure; the point in a curve or surface at which the axis meets it; an angular point, as of a triangle or polygon.

axis: (n) The geometrical line, by the revolution of a superficies about which, solids with circular section, as a globe, cylinder, cone, etc. are conceived to be generated.

superficies: (n) A magnitude of two dimensions, having only length and breadth; that which forms the boundary or one of the boundaries of a solid, or separates one part of space from another; a surface.

focus: (n) In plane geometry: One of the points from which the distances to any point of a given curve are connected by a linear relation.

latus rectum: (n) a straight line drawn through the focus of a conic at right angles to the transverse diameter, the parameter.

There, that all makes sense now, right?

Comments

[gwynraven.livejournal.com]

I miss math. I really enjoyed all my math classes. I took Vector Calc in college for *fun*. It wasn't even required for my major. Now most of my job is subjective. Not that I don't love it, but every now and then I miss proofs.

[wakingdreaming.livejournal.com]

Relearn? I never learned it in the first place. Seriously, I never got that far in my math classes.

[islandisee.livejournal.com]

math and girls are a sexy combination! ;-)


Seriously, I have loved tutoring a bit in pre-cal and trig for my brother and another girl from his school. I miss the beautiful logic and puzzle-solving of math.

[poldybloom.livejournal.com]

I prefer algebra to geometry..the Principia always intimidated me.
I'm pretty sure most physicists never actually read the thing.

[gwynraven.livejournal.com]

It's actually kind of interesting. I don't understand all of it, but it's night reading about stuff I learned in basic physics as if it was a new theory.