March 26

# Week6 — Math 10

This week I learnt Trigonometric Ratios. From the questions on the workbook, I summed up some rules:

Rule I1) sin x˚, sin y˚,  if x>y, so  sin x˚>sin y˚

2) cos x˚, cos y˚, if x>y, so cos x˚<cos y˚

3) tan x˚, tan y˚, if x>y, so tan x˚>tan y˚

4) sin x˚, tan x˚, so sin x˚< tan x˚.

Rule II: sin x˚, cos x˚

1) x<45˚               sin x˚< cos x˚

2) x=45˚              sin x˚= cos x˚

3) x>45˚              sin x˚> cos x˚

There is also a very important rule is cos x˚=sin (90 – x)˚ and sin x˚=cos (90 – x)˚.

March 6

# Week 5 — Math10

The most difficult things I learnt from this week is the “Conversion of Units within the International System of Units (SI)” There are lots of units like feet, inch, yard, etc. I did not learn before. These units always make me confused, and I am a little bit worrying about my next week test.

There is a very difficult question I found in this week. At last, I got it, so it is my Ah-ha moment.

The question is: Convert the following to the indicated measurements using unit analysis.

a)120m/h=____mm/min

When I saw this question I was speechless because I have no idea! But later, I studies the example, and I got a method to solve this question.

Here is my method. Just convert each part of the indicated measurement. And then, just divide 120×10^3mm by 60min, so the answer is 2×10^3mm/min.

March 4

# The Character Sketch — The Stolen Letter

————- The Detective ‘Dupin’ —————-

In “The Stolen Letter,” Dupin is the famous detective in Paris who is able to solve the mystery in the story because he is a cautious, skilled, and intelligent detective. Firstly, even though the chief is an expert investigator, he needs Dupin’s help.  The chief states, “I need your assistance. You are an expert in these investigations. You have done this many times before.”  This shows that Dupin is a skilled and intelligent detective. He can resolve lots of difficult cases because he is an experienced and believable detective. He also infers that the Minister is a very smart and dangerous man from the chief’s description. This shows he is very intelligent. Dupin asked a number of questions but only told the chief to check the house again because he had a better idea of how to solve the mystery. During that one month, he got the letter which shows that he is clever. First, he wore a pair of dark glasses to enable himself to look carefully around the minister’s office without him noticing. When he found the letter, he just left while thinking about a good idea to “steal” the stolen letter back. His reason to return to the minister’s house was to get back the glove he left there on purpose. Dupin also paid someone to district the minister so he could switch the letter. Not only does this show how clever Dupin is, it also shows that he is a cautious man because he planned a perfect plan to get the letter without the minister noticing. He knew he could not get that letter under the Minister’s nose, because he is a really dangerous man. Dupin carefully his skills to successfully solve the mystery of the stolen letter.