Authors: Paul Kleinman
Reciprocal Identities
Identities are true no matter what value the variable is. For example, the problem (
x
+ 3) (
x
– 3) =
x
2
– 9 is always true. That makes it an identity. In trigonometry, there are several reciprocal identities one has to know.
The reciprocal identities are:
Brownian Motion
In 1905, Einstein’s third paper concentrated on the random movement of small particles in liquids and gases. Brownian motion gets its name from Robert Brown, who in 1827, reported on the motion of pollen particles in water. Brown, however, was never able to figure out why the motion happened. Einstein figured out that the motion was due to water molecules hitting the pollen. Though the pollen grains were visible, the water molecules weren’t, and so it appeared that these particles were jiggling. Einstein was also able to show the speed the water molecules were moving in and how many molecules hit a single grain of pollen, as well as what properties of atoms could be tested.
Cantonese Today
A total of 71 million people speak Cantonese, and it is spoken in Hong Kong, Guangdong, Macau, Hainan, and Guangxi. Through Western colonialism, migration, and trade, the majority of Chinese who have traveled abroad have been speakers of Cantonese. Today, Cantonese-speaking communities appear more in other countries than in most of China. The United States and Canada have the most
Cantonese-speaking communities outside of Hong Kong and mainland China, and in San Francisco, there are a total of 180,000 Cantonese speakers.
The Aftermath
Lenin’s peace policy with Germany was widely unpopular and ended in Russia ceding large territories to the Germans. Following the October Revolution, a civil war broke out between the Whites (the anti-Bolsheviks) and the Reds (the Communists). The Reds eventually won after four years, and in 1922, the Soviet Union was established. When Lenin died in 1923, Joseph Stalin came to power.
David Sedaris
David Sedaris (whose sister is comedian Amy Sedaris) is one of the most prolific humorists writing today. His books usually consist of short essays full of biting, absurdist, and slightly neurotic commentary, based on his life. One of his most famous pieces, “Santaland Diaries,” was a memoir of his seasonal job working as an elf for Macy’s during the holiday season. He has published many books of his essays, one of his most well known being
Me Talk Pretty One Day
.
Inverse Trigonometric Functions
When given the value of a function and asked to find the value of the angle, this is referred to as an inverse trigonometric function. The terms used for inverse functions are
arcsin
,
arccos
,
arctan
,
arccsc
,
arcsec
, and
arccot
. If
f
(
x
) = sin x and
g
(
x
) = arcsin
x
, then the formula for finding the inverse trigonometric functions is
f
(
g
(
x
)) =
x
or
g
(
f
(
x
)) =
x
. So arcsin
x
=
y
, which leads us to the formula
x
= sin
y
.
His Brain
Albert Einstein died on April 18, 1955, at the age of seventy-six. His body was cremated, but his brain was saved for research. Until 1999, it was decided that Einstein’s brain was really no different than any other person’s brain. In 1999 however, it was discovered that Einstein’s brain lacked a certain wrinkle, called the parietal operculum. To compensate for this lacking wrinkle, other parts of his brain, such as the inferior parietal lobes, had to compensate. This part of the brain plays a role in mathematical thinking and visual imagery.
Useful Cantonese Phrases
Here are some helpful phrases to use when traveling to Hong Kong. Note that these are written in Yale Romanization, a phonetic English alphabet:
Hello.
Néih hóu.
Pleased to meet you.
Hóu hòisàm yihngsīk néih.
Good morning.
Jóusàhn.
Good day.
Ńgh ōn.
Good evening.
Máahn ōn.
Excuse me.
m̀hgòi.
How much is this?
Nīgo géidō chín a?
Thank you.
Dòjeh.
Where’s the toilet?
Chisó hái bīndouh a?
Do you speak English?
Neih sīkm̀hsīk góng yìngmán a?
Can you translate it for me?
Néih hóm̀hhóyíh bòng ngóh fáanyihk a?
Goodbye.
Joigin.
Lenin’s successful coup d’état, in which he and the Bolshevicks overthrew the Provisional Government, describes which of the following events?
Which of the following happened after Lenin came to power?
Which of the following was written by Mark Twain?
The Hitchhiker’s Guide to the
Galaxy
was written by:
What is 60° in radians?
There is an oblique triangle ABC with side
a
= 9 inches, side
b
= 11 inches, and the angle of
C
is 60°. What is the value of
c
?
What can we derive from
Einstein’s special theory of
relativity (
E
=
mc
2
)?
Einstein’s theory of relativity can be broken up into what two parts?
Which of the following is true?
Which of the following is true?