Calculus I

Calculus I in high school: the big picture

Calculus studies change and accumulation. Derivatives answer “how fast?” at a single moment. Integrals answer “how much built up?” over an interval. Most first courses spend a lot of time turning those ideas into reliable routines you can do on paper without a computer.

Limits: the language of “almost there”

A limit describes what a function is approaching as x nears a value—not always what the function equals at that spot. Limits explain holes, jumps, and why some formulas only work when you simplify carefully.

  • Left vs. right: Approach from one side at a time; both must agree for a two-sided limit to exist.
  • Continuity (practical version): You can draw it without lifting your pencil—no gap, no wild jump—at that point.
  • Algebra tricks: Factoring, rationalizing, or comparing to a known limit can remove a 0/0 form.

Derivatives: slope of the tangent line

The derivative is the slope of the tangent line—the line that barely kisses the curve at a point. On a motion graph, slope is speed; on a cost curve, it can be marginal cost once your teacher defines it precisely.

Rules you will drill until they feel automatic:

  • Power rule: bring down the exponent, drop the power by 1.
  • Product and quotient rules: for multiplying/dividing two functions.
  • Chain rule: for “function inside a function,” like sin(3x) or (2x + 1)⁷.

What derivatives are for (besides tests)

Derivatives locate local max/min and help read where a function increases or decreases. Sketch sign charts, label critical points, and connect the picture to the story your word problem is telling.

Integrals: area and antiderivatives

An indefinite integral is a family of antiderivatives (+ C). A definite integral is a number—often interpreted as signed area between a curve and the x-axis. The Fundamental Theorem links “area so far” back to the original function you started with.

Expect lots of practice with substitution (reverse chain rule) and simple area setups. Keep limits of integration straight: changing variables means changing those bounds too.

Quick review checklist

Run this on paper the night before an assessment—short answers, no peeking.

  • Vocabulary: Five terms, defined in your own words.
  • One strong example: Problem, diagram, quote+context, or map label your rubric would accept.
  • Classic trap: What mistake shows up on every test—and what rule stops it?
  • Connection: One sentence linking this topic to another unit from the same course.