Deep Dive: Tuesday, September 29
September 29th — The Date That Separates Students Who Are Ready From Those Who Think They Are
There's something that happens in late September that I've watched play out with hundreds of students over the years. The initial rush of a new school year has worn off. The AP class syllabi that looked manageable in August are starting to feel real. And the students who coasted through the first few weeks on summer momentum? They're starting to feel the ground shift under them. If you're reading this on or around September 29th, here's what I want you to know: you're at exactly the right moment to make a course correction — or to double down on what's already working.
This post covers something across almost every subject area. Not a single topic, but a single principle — the idea of going back to first principles. Whether you're working through AP Calculus, struggling with organic chemistry, writing economics essays for IB, or trying to crack SAT math, the students who make the biggest gains between now and May are the ones who stop skimming the surface and start understanding why things work.
What "First Principles" Actually Means (It's Not What You Think)
I hear this phrase thrown around a lot, and it gets misunderstood. First principles thinking doesn't mean going back to chapter one and re-reading everything. It means asking: what is the most basic, irreducible truth here, and can I rebuild the concept from that point?
Here's a concrete example. In AP Calculus, a lot of students can differentiate using the power rule without any hesitation. Ask them to derive the power rule from the limit definition of a derivative? Silence. That gap matters — not because the AP exam always asks for derivations, but because when something breaks down in a problem, students who understand the foundations can troubleshoot. Students who only know the shortcut are stuck.
Same thing in AP Physics. You can memorize F = ma. But if you understand that Newton's second law is really a statement about how net force changes the rate of change of momentum, suddenly circular motion, impulse-momentum problems, and even some electrostatics questions start to make more sense. The formula is a summary. The principle is the actual knowledge.
Mathematics: Calculus, Algebra, and the One Thing Students Always Get Wrong
Let me talk about calculus for a second, because it's where I see the most students hit a wall around this time of year — specifically AP Calculus AB and BC students, but also IB Mathematics students working through the Analysis and Approaches Higher Level course.
The most common mistake I see isn't algebraic errors (though those happen constantly). It's a conceptual one: students treat the derivative and the integral as separate, unrelated tools. They don't feel, in their bones, that they're inverses of each other. When you really get the Fundamental Theorem of Calculus — not just the statement of it, but what it's saying — the whole subject changes. It's saying that accumulation and rate of change are two sides of the same coin. That's it. That's the whole thing.
Try this: before your next practice test, pick one formula you use all the time and ask yourself if you could explain it to a 12-year-old. If you can't, that's your study priority for the week. Not the hardest problem in your textbook — the most basic explanation of something you thought you already knew.
A Quick Worked Example: Implicit Differentiation
Students consistently find implicit differentiation confusing because they forget what they're doing. You have an equation where y is implicitly a function of x — it's just not written that way. When you differentiate both sides with respect to x, and you hit a term with y in it, the chain rule kicks in automatically. That dy/dx that appears isn't magic. It's the chain rule applied to a function you haven't explicitly named yet.
Take x² + y² = 25. Differentiate both sides: 2x + 2y(dy/dx) = 0. Solve: dy/dx = -x/y. Notice we left the answer in terms of both x and y — and that's completely fine, because y is still a function of x, just one we haven't isolated. Once that clicks, the whole process becomes mechanical in the best possible way.
Chemistry, Biology, and Environmental Science — The Subjects Where Memorization Lies to You
If you're in AP Chemistry right now, there's a real temptation to treat thermodynamics as a memorization exercise. ΔG = ΔH - TΔS. Fine. But do you understand what spontaneity actually means at the molecular level? Entropy isn't disorder in the casual, messy-room sense — it's about the number of microstates available to a system. When you understand that, the signs and conditions for spontaneity aren't things you memorize. They're things you reason through.
AP Biology has its own version of this problem. Students spend enormous energy memorizing the steps of cellular respiration — glycolysis, pyruvate oxidation, the Krebs cycle, the electron transport chain — without ever connecting it to the central question: how does chemical energy in glucose become ATP that a cell can actually use? The mechanism is the story. Learn the story and the steps follow naturally.
For students doing Environmental Science — whether AP or IB — the same principle holds. You need to understand systems thinking. Everything is connected to everything else, and the exam is going to ask you to trace those connections.
Economics, Business Studies, and Accounting — Where the Numbers Have to Tell a Story
Here's something I tell every economics student I work with: an answer that's mathematically correct but economically illiterate will lose marks at every level. Whether you're in AP Economics, IB Economics, or taking a college-level microeconomics course, the evaluators want to see that you understand what's happening in the real world, not just that you can draw a supply-and-demand diagram.
Take price elasticity of demand. Most students can give you the formula. Fewer can tell you why a firm with a product that has inelastic demand can raise prices without losing significant revenue — and what that implies for market power, for consumer welfare, for regulatory intervention. That chain of reasoning is the actual skill being tested.
If you're working on financial accounting — especially if you're taking a college course and looking for an online tutor who can help you work through balance sheets and income statements — the same principle applies. Debits and credits are just a recording system. The real skill is understanding what the numbers are communicating about a business's health.
English, Psychology, Sociology — The Essay Subjects That Reward One Specific Thing
I want to say something a bit blunt here. In AP Language, AP Literature, IB English, or any of the social science essay subjects: the students who score highest are not necessarily the ones with the biggest vocabulary or the most sophisticated arguments. They're the ones who are most precise.
Precision in essay writing means your evidence directly supports your claim. It means your claim directly addresses the question. It means every sentence is doing a job. I've read student essays where the ideas were genuinely impressive but the score was mediocre because the student couldn't stop themselves from including everything they knew rather than everything that was relevant. Relevance over volume. Every time.
For psychology and sociology students — especially those prepping for AP Psychology or IB Psychology — the command of studies and research methodology is what separates good answers from excellent ones. Know your studies cold, yes. But also know what each study actually demonstrates, what its limitations are, and why those limitations matter for the conclusion you're drawing.
Computer Science, Statistics, and Data Science — The Most Underestimated AP Subjects
AP Statistics is probably the most practically useful course in the entire AP curriculum, and I don't think it gets enough credit. If you're heading to any college major that involves data — which in 2024 is almost everything — understanding p-values, confidence intervals, and regression isn't optional background knowledge. It's foundational.
The first principles move in statistics is always the same: what question are we trying to answer, and what kind of data and analysis gives us a valid answer? Students who anchor every problem to that question make far fewer errors than students who jump straight to formulas. If you're looking for an online tutoring plan that covers AP Statistics or AP Computer Science Principles with personalized support, it's worth getting that foundation solid before the exam season intensifies.
Finding the Right AP Tutor Online — What Actually Matters
A lot of students start looking for an AP Calculus tutor online or an AP Physics tutor around this time of year, and the instinct is right. But here's what I'd tell you to look for: not someone who will just do extra practice problems with you, but someone who will diagnose the specific conceptual gaps that are causing your errors. Extra practice on top of a misunderstanding doesn't fix the misunderstanding — it reinforces it.
The best tutoring conversations I've had with students started with me asking them to explain a concept back to me before we did a single problem. What they said — and what they couldn't say — told me everything about where to start. If you want to experience that kind of targeted, diagnostic support, you can start your free 21-day trial and get matched with a tutor who specializes in exactly what you need, whether that's SAT math, IB Chemistry, AP Macroeconomics, or anything else across the curriculum.
The One Non-Obvious Thing I Want You to Take From This
The students I've seen make the most dramatic improvements between September and May aren't always the most naturally talented. They're the ones who got genuinely curious about the subjects they were studying. Not because curiosity is a nice character trait, but because curiosity drives the kind of questioning — why does this work, what does this actually mean, how does this connect to that — that builds real understanding rather than surface-level familiarity.
September 29th. You've got roughly seven months to the AP exams, about the same to IB finals, and SAT test dates are already on the calendar. That's a significant amount of time if you use it with intention. It's almost nothing if you're just putting in hours without building understanding.
Go back to first principles on one topic this week. Just one. See what happens to everything else around it.



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