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Whole-book reading guide from stratified index samples; jump to passages in the text
AI guide
【One-Line Pitch】
A gentle, plain-language reintroduction to calculus for anyone who was frightened off by formal textbooks: it teaches you to read the symbols, trust small quantities, and actually differentiate. Best for self-learners, students in their first calculus course, and adults who want intuition before rigor.
【Book Arc】
- **Opening (~0%–10%)**: Defuses calculus anxiety by explaining the two core symbols — the "little bit of" d and the long-S sum — and by showing why higher-order small quantities can be ignored. It solves the psychological barrier before any technique.
- **Early (~10%–32%)**: Builds differentiation from first principles: powers, constants, sums, products, quotients, repeated differentiation, and the chain-rule "trick" of substitution. The problem solved is mechanical fluency with algebraic expressions.
- **Middle (~32%–48%)**: Turns derivatives into geometry — slope, tangents, intersections of curves, and the use of dy/dx = 0 to locate maxima and minima. This is where calculus becomes a tool for optimization.
- **Late (excerpts do not cover)**: The sampled material stops around maxima/minima and curve sketching; later chapters on trigonometric, exponential, and integral topics are not represented in these excerpts.
- **Ending (excerpts do not cover)**: No closing chapters, appendices, or final review material appear in the sampled chunks.
【Key Takeaways】
- **Calculus is presented as a language of small increments, not a wall of theorems** (Opening): the book insists that dx means "a little bit of x" and ∫ means "the sum of all the little bits," which reframes intimidating notation as ordinary addition and division.
- **Ignoring higher-order small quantities is the central mental habit** (Opening): the square-of-a-sum example shows why (dx)² vanishes while 2x·dx survives, and this single idea powers nearly every derivation that follows.
- **Differentiation is taught as finding a growth ratio** (Early): the reader repeatedly asks "how fast does y grow when x grows?" rather than memorizing rules, so dy/dx emerges as a rate before it becomes a formula.
- **The power rule is derived, not announced** (Early): x², x³, x⁴, x⁵, negative powers, and fractional powers are all worked out from first principles before the general nx^(n−1) rule is stated.
- **Constants disappear under differentiation, and constant multipliers survive** (Early): adding 5 or multiplying by 7 changes the curve but not its slope, which clarifies what differentiation actually measures.
- **Product and quotient rules are justified by the same small-quantity logic** (Early): the book derives both rules from (u+du)(v+dv) and from long division, treating them as consequences rather than arbitrary formulas.
- **Repeated differentiation reveals structure** (Early): differentiating x⁵ five times collapses to a constant and then to zero, introducing f′(x), f″(x), and the factorial pattern.
- **Derivatives describe motion and geometry simultaneously** (Early–Middle): velocity and acceleration problems sit alongside slope and tangent problems, showing that the same operation answers physical and visual questions.
- **Maxima and minima are found by setting the derivative to zero** (Middle): the book frames this as the most useful application, with worked examples on rectangles in circles, conical volumes, and curve sketching.
【Reading Tips】
- **Read the opening chapters slowly and do not skip the small-quantity discussion.** Everything later depends on being comfortable with discarding (dx)² and higher terms; if this feels hand-wavy, that is intentional — the book prioritizes intuition over rigor.
- **Work the exercises as you go.** The excerpts are dense with practice problems (powers, products, quotients, motion, optimization); the book's method is learn-by-doing, and reading solutions passively will not build fluency.
- **Skim the historical asides on Newton's fluxions and Leibniz's notation** if you want technique quickly, but return to them if notation choices confuse you — they explain why dy/dx and ẏ coexist.
- **Deep-read the maxima/minima chapter.** It is the clearest bridge from mechanical differentiation to real problem-solving, with engineering-flavored examples about cost, efficiency, and volume.
- **Keep a sketchbook.** The book repeatedly tells you to draw the curve; graphing y and dy/dx side by side is how it makes the derivative visible.
【Coverage Limits】
This guide is based on stratified excerpts covering roughly the first half of the book, from the preface through maxima and minima. Later chapters on trigonometric, exponential, and integral calculus are not represented, so claims about the book's full treatment of those topics cannot be made from this sample.
Excerpt 1
忽略不计。由此可以推论,在任何情况下,当所选的第一阶的微量取足够小时,我们就完全可以忽略第二阶、第三阶或是更高阶的微量。 不过必须牢记的是,当这些微量作为因子与其它因子相乘时,若其它因子很大,这些微量也将随之增大。哪怕只是乘上几百,连不起眼的1法新也会变得举足轻重了。 现在回到微积分上面来,我们将dx看成是一丁点...
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Excerpt 2
数式的微分,本章后面的习题也能独立解决了。 (1)对 求导。 这个常量是可以被消去的。 立即得到: 或 (2)对 求导。 消去常数项 ,并将 用指数形式表示为 ,可得: ,或 。 (3)若 ,求 y 对x 的导数。 求解这类表达式,通常需要多掌握一些知识,但是,我们不妨试试看,是否可以将它化成更简单的形式。 首先...
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Excerpt 3
可以得到v=0.6t 2 −6t; a=1.2t−6。加速度不再是一个常数。 当t=0,x=10.4,v=0,a=−6。此刻物体是静止的,但是已经做好了以负加速度运动的准备,也就是说,即将获得朝向O点运动的速度。 (5)如果x=0.2t 3 −3t+10.4,则有v=0.6t 2 −3,a=1.2t。当t=0,x...
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Excerpt 4
找到y为极小值(或极大值)时对应的x值,先对等式求微分,完成以后,写出 的表达式,并令其等于0,然后解这个关于x的方程。将求得的x值代入原方程,你就能算出你想要的y值了。人们通常把这个过程叫做“令某某式子为零”。 现在让我们通过本章开头的例子,感受一下上面提到的方法有多么简单,等式如下: 图27 微分求导可得:...
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Excerpt 5
我们实际算得的部分公式完全相同,这样一来就真相大白了。 可以看到,我们只需令分子均为数值项,就能求出终极版的部分分式啦。 但是,当多重因式包含x 2 时,对应的分子就必须以Ax+B的形式存在;譬如, 从而得到3x−1=(Ax+B)(x+1)+(Cx+D)(x+1)(2x 2 −1)+E(2x 2 −1) 2 ;...
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Excerpt 6
一段时间t后的温差,a是一个常量——也叫做衰减常数,与物体暴露在环境中的面积有关,也与该物体的导热性与散热性等性质有关。 一个类似的公式 图42 Q t =Q 0 ε −at 描述了一个充电物体中电荷逐渐流失的过程,初始电荷量为Q 0 ,衰减常数为a;在本例中,该常数与物体的电容与电荷泄漏通道的电阻有关。 一个自...
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Excerpt 7
C,于是可得斜线方程为:y=ax+C。 图48 显然地,在任何情况下我们加上一个常数,就可以得到当x=0时对应y的取值。 现在来看个更棘手一点的例子,当一条曲线斜率并非常数,且会逐渐增时,想象一下,随着x增加,曲线向上的倾斜度将按比例增大。用符号可以表示为 .或者更具体一点,比如给定 ,则 。 以x取不同数值为例...
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Excerpt 8
和QN=y 2 。这样我们就标出了PQ与x轴之间所夹的不规则图形,记作PQNM。现在问题来了:我们该如何计算它的面积呢? 设想一下:把这个图形分割成大量窄小的片状,每份的宽度都是dx——这就是本题的解题法门了。dx取得越小,x 1 和x 2 之间的部分就越多,且全部这样的细片面积加在一起,就可以得到整块阴影图形的...
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