Stated/Geometry Questions

[murali0298]

Can anyone answer the following:

From 2010 Invitational A.

10 A # 39
10 A # 40
10 A # 50 (I got 2.41 as my answer but the key says 2.81)
10 A # 57
10 A # 60

Thank you.

[murali0298]

Another Question::

How do I do problems like this:

57893^453562? My Ti 89 says infinity!

[darksaber21]

[darksaber21]

[murali0298]

[darksaber21]

Yeah, they are. Not all the formulas are there, however, at least from what I've seen. But laws of sines and cosines are in there.

And that's how I would do #40.

And number crunchers tend to be the same throughout tests (from Inv. to district and so on), with only the geometry and stated getting harder as time goes on.

[darksaber21]

[murali0298]

[darksaber21]

Well, the length and width of the base is the diameter of the circle, right? But here's the thing, I changed it to 2r so I can use the volume formula of the cone using r. If I used the diameter for the length of the cone, the volume of the cone would have to be changed to [unparseable or potentially dangerous latex formula]. That's what you did wrong, you used incorrect lengths I believe. You must use either the radius in both volume equations or the diameter, keeping the fact that the diameter is twice the radius. Did that help?

[darksaber21]

Also, when using that formula, it helps to factor out the height and radius squared, since you are diving by [unparseable or potentially dangerous latex formula] (if looking for diameter), or [unparseable or potentially dangerous latex formula] (when looking for radius)

[darksaber21]

[darksaber21]

[darksaber21]

[murali0298]

[darksaber21]

You can expect it at least about once or twice a year. Also, it is possible for that type of problem to be disguised as a stated problem.

[007math]

[nsguy1350]

[88bobcat]