想請問這題🙏，有點看不懂圖三的公式是從何而來，卡住了

EXAMPLE 21.11 FIELD OF A UNIFORMLY CHARGED DISK A nonconducting disk of radius R has a uniform positive surface charge density o. Find the electric field at a point along the axis of the disk a distance x from its center. Assume that x is positive. SOLUTION IDENTIFY and SET UP: Figure 21.25 shows the situation. We rep- resent the charge distribution as a collection of concentric rings of charge dQ. In Example 21.9 we obtained Eq. (21.8) for the field on the axis of a single uniformly charged ring, so all we need do here is integrate the contributions of our rings. EXECUTE: A typical ring has charge dQ, inner radius r, and outer radius r + dr. Its area is approximately equal to its width dr times its circumference 2πr, or dA = 2πr dr. The charge per unit area is σ = dQ/dA, so the charge of the ring is do = o da = 2πor dr. We use dQ in place of Q in Eq. (21.8), the expression for the field due to a ring that we found in Example 21.9, and replace the ring 21.25 Our sketch for this problem. Idr dQ X P dEx dEx radius a with r. Then the field component dEx at point P due to this ring is 1 2πσrx dr 4π€0 (x² + ²)3/2 SOLUTION Continued

我想請問 原本fn只在所有compacts上一致收斂 D裡面會不會也包含沒辦法closed and bounded的部分 但我最後要證明的卻是在整個D上f都連續 這樣①③的選擇會不會只證明f在D中的任何compacts連續呢 如果會的話要怎麼改善證明 （高微證明小白求解..

Question 2 [10] Let {fn (2)} be a sequence of continuous complex functions defined on D C C and f(z) be a complex function defined on D. Prove by e-N definition that if fn(z) converges uniformly to f(z) on compacts in D, then the limiting function f is also continuous. 0₁0. fn 3 f for z For every Z in K E > = N(6) € ₁ s.t. Unz N₁ | fn (2) - f(z)] < 1/10 N= . in any compact sets K≤p. @fn 75 20, 2 820 sit.lzx]<8>lfe)-f(x)]<- continuons for z in D. For every z, & in D. VE>O, we choose the above N and f if Iz-*|< 8, then s.t | f(2)= f(a)| = |f₁z) - fn(z) + tn (2) - fn(x) + fn(x) – frasl ≤ | fn(z) - f1z)| + | fn(²2) - fn(x) |+| fricas) _flox) | = D E 1/4 + 1/3+1/²/3 = 3 =.E.

請問大一統計學這兩題有人看得懂嗎🥲

2. To study the attitude of mother and father towards their daughter participating in the outdoor games, a sample of 200 fathers and 250 mothers was investigated. In these two samples, 120 fathers and 50 mothers preferred their daughter to go for outdoor activities. Can it be concluded at a=0.01 level of significance that the proportion of father is significantly higher than that of mother in preferring their daughters for outdoor activities? 3. A firm has a generous but rather complicated policy concerning end-of-year bonuses for its lower-level managerial personnel. The policy's key factor is a subjective judgment of "contribution to corporate goals." A personnel officer took samples of 24 female and 36 male managers to see whether there was any difference in bonuses, expressed as a percentage of yearly salary. The data are listed here: Gender Bonus Percentage Female 9.2, 7.7, 11.9, 6.2, 9.0, 8.4, 6.9, 7.6, 7.4, 8.0, 9.9, 6.7, 8.4, 9.3, 9.1, 8.7, 9.2, 9.1, 8.4, 9.6, 7.7, 9.0, 9.0, 8.4 10.4, 8.9, 11.7, 12.0, 8.7, 9.4, 9.8, 9.0, 9.2, 9.7, 9.1, 8.8, 7.9, 9.9, 10.0, 10.1, 9.0, 11.4, 8.7, 9.6, 9.2, 9.7, 8.9, 9.2, 9.4, 9.7, 8.9, 9.3, 10.4, 11.9, 9.0, 12.0, 9.6, 9.2, 9.9, 9.0 (1) Is there significant evidence that the mean bonus percentage for males is larger than the mean bonus percentage for females? Use a a=0.05. (2) Estimate the difference in the mean bonus percentages for males and females using a 95% confidence interval. Male

歷史有什麼比較好背的方法嗎？

我找不出來

選出正確的句子: (A) It was less cold yesterday than today, so I did not turn on the fan during the night.. (B) For Linda, letting her kids eat too much fast food is the least thing to do. She cares more about their health. (C) Jay is poor at studying math. For him, playing basketball has much more fun than studying math. (D) Swimming in the river looks like fun, but the water safety is the most important thing to remember.

為什麼答案是A

(A). gone (C) hag Studying in a apartment. (A) cost You should think (A) happily (C) quickly prop D foreign country Dis. (B) lost AAliceffearned from the TV news that B) where 13. The weather is going to be really your trip. (A) clear but windy my family they after eleven o'clock. (D) we to the beach for two days. (B) went (D) will go me a lot of money. That's why I had to sell my (C) made (D) spent before taking the job; don't do it just for fun. (B) proudly (D) seriously (Nora Jones was coming to Taiwan the next day.) (C) which (B) cold but dry (whether 9 so I don't think you should take a heavy coat (C) cool and wet (D) hot and sunny

求解

A" 班級: 第三次定期考查 座號: 姓名: 本B1 U7-R3,開麥拉 Ch7、Chll、Ch12;核單 Level 3 U17-24;雜誌 12月 in the kitchen. 18. When Messi was watching World Cup in the living room, he smelled the fish. (A)burn (B)burns (C)burned (A)let 19. Joey is sad because his father doesn't (B)allow (A)named 20. Anna has three uncles. The one A him study in Japan. (C)made her when she was born is her favorite. (C)name (B)naming 科目:英語文 (D)burning 第5頁,共7頁 (D)have (D)will name

第1、4題答案

五、克漏字選擇:16 分(每題4分) Dear John, This is not the life 1. I want, and I can't stand it anymore. We 2. for more than six years. However, 3. . I cooked the meals, did the dishes, cleaned the house, watered the plants, took out the garbage, and picked up our kid-all by myself. When you got home from work, you always said 4. you were too tired and just wanted to relax. In fact, I felt tired, too. I'm your wife, not your housekeeper. If you don't make any change, I will never get back. Call me after you figure out what to do. Rebecca stand relax housekeeper figure out ( (D) 2. (A) marry ) 1. (A) what (B) and (C) it (B) married (D) that (C) have married (D) have been married ( A ) 3. (A) I appeared to be the only one that took care of our family (B) you always repeated what I said back to me (C) I was the wisest one in the family (D) you never passed up any chances to do housework ) 4. (A) which (B) that (C) what (D) if

為什麼第7題不選D選A，求解？？

2676 1st: 43 The scientists decided to light fires that would burn off the gas, figuring that it would only be a few weeks 4. the gas was all gone. They evidently made a miscalculation, as the fires have been burning constantly for over 40 years. In 2010, the president of Turkmenistan VR recommended that the Stater* (should) Ver 5. filled in to limit the amount of gas that is burned. However, no action has yet been taken. Thus, the Door to Hell remains firmly open, drawing tourists from all over the world to gaze into its fiery depths. 事 3. to those who live nearby. 1. Adultimately (B) respectively 2.(A) coming down ( (B) blending in 倒塌 (A) menace FATA 4. (A) until 5 A) was 3 fa (C) approximately (C) giving in 威育恐嚇 (B) hypocrisy 飾 (C)facility 設施) (B) when (C) before to be (B) be Partid 199 a 201 (D) constantly (D) going out Right (D) legacy 產 Dif (D) had been While scientists are 6. to find ways of improving plants, medicine, and human beings, many arguments are being 7. . Some arguments may be personal, social, or economic but more likely, they tend to be moral. And it is believed that genetic engineering will keep on mmm. 工程学 changing us throughout this century. 8. genetic In general, people question the whole use of genetic engineering. engineering will improve the way we grow food and care for our environment, people still question genetic engineering. What may be questioned is how companies may 9. their 2023/01/03 19:55 use. and h how is, c que exp sce in te re C

有人有二模各科詳解嗎？