June 2016 Geometry (Common Core) Regents

Good night… I-)

What time does everyone’s exam start tomorrow? Ours is very late, from 12:50 pm, ending at 3:50 pm

Mine starts at 12:00pm

Mine is at 12:00

Hey, I was packing my stuff for tomorrow and have a question:

I have a TI-30X and a TI-83+, but I am more comfortable using the TI-30X. Can I use both at the regents tomorrow because I don’t know if I may want to do a graph or something that would require my TI-83+?

I’m sure you can use both, I don’t see any possible reason as to why they would care. By the way, should we know irregular sin / cos / tan (ie sin 30 45 60)?

I don’t see a reason why you need to memorize them. If it shows up, draw a diagram

diagram?

While it’s not necessary to memorize those values, definitely remember the values of sides in special right triangles
I.e. a 30 60 90 triangle has the following side measures: opposite 30°=x. Opposite 60°=x (rad 3). Opposite 90°=2x

oh alright, thanks.

You would not need to know the ratios, but they could be useful for some problems.
For example, question 11 on the August '15 exam was:

Linda is designing a circular piece of stained glass with a diameter of 7 inches. She is going to sketch a square inside the circular region.

To the nearest tenth of an inch, the largest possible length of a side of the sqaure is

(1) 3.5
(2) 4.9
(3) 5.0
(4) 6.9

The correct newer is 2 because you can just divide 7 (the diagonal of the sqaure) by radical 2. This is closest to 4.9. You could use SOH CAH TOA and get the same answer though: sin or cos 45 = (x/7). Then, 7cos45 is closest to 4.9.

There are lots of “tricks” you can know just to solve problems more easily. For example, you can use the formula area = (radical 3)(.25)(s^2) for any equilateral triangle, where s is a side’s length. However, you could also just use trig to find the altitude and then multiple the altitude by the side and divide by two.

Do any of you know if they would ever require an exact answer for trig like: a field shaped like an equilateral triangle has a side length of 6 miles, find the exact area of the field in sqaure miles.

For the stained glass question, why did you divide by radical 2?

The sqaure has a 45-45-90 right triangle in it where two of its sides are legs and the diagonal (7) is the hypotenuse. There is a trick with 45-45-9 right triangles that the hypotenuse is equal to one of the legs times radical 2. So, I just divided 7 by radical 2 to get one of the sides of the sqaure.

If that does not make sense, just use the pythagorean theorem, let x be a side of the square: x^2+x^2=7^2. This means 2x^2=49. Divide each side by two and ×^2=24.5, so our answer is radical 24.5, which is also equal to 7 divided by radical 2.

Oh I see, thank you.
Is there anything else I should know for today’s exam?

Pretty good link for proofs:http://www.regentsprep.org/regents/math/geometry/gpb/theorems.htm

Is it weird that I put juice in my cereal (as opposed to milk)? :-/

yes I think it’s weird

Guys we all should cheat for his test and give the answers in here

Would anyone be willing to put there multiple choice answers in here ?