AP Calc AB units: All 8 units, exam weightings, and where to focus

AP Calculus AB is organized into 8 CED units, and CollegeBoard weights them differently on the exam. The heaviest unit is worth about three times the lightest, so if you plan revision without checking the weightings, you'll spend equal time on all 8 and still walk in under-prepared for the heaviest topics.

This guide covers all 8 units, their weight, what's inside each, and where to spend your time first. If you want to practice against the exact format the exam uses, Cognito's AP Calculus AB past papers library has released papers with worked solutions.

Unit 1 covers limits (analytically, graphically, from tables), one-sided limits, infinite limits and vertical asymptotes, limits at infinity and horizontal asymptotes, continuity, and the Intermediate Value Theorem.

What to prioritize: Evaluating limits algebraically (factoring, rationalizing, L'Hopital's rule which returns in Unit 4), recognizing when a limit is indeterminate, and using continuity to solve for unknown parameters.

Unit 2 covers the definition of the derivative, differentiability, rules for derivatives (power, product, quotient), and derivatives of trig functions and e^x.

What to prioritize: The limit definition of the derivative, product and quotient rules with common trig combinations, and recognizing when a function is not differentiable (corners, cusps, discontinuities, vertical tangents).

Unit 3 covers the chain rule, implicit differentiation, derivatives of inverse functions, and derivatives of ln(x) and inverse trig functions.

What to prioritize: Chain rule fluency (this is used in every subsequent unit), implicit differentiation on equations mixing x and y, and the derivative-of-inverse formula for exam-standard problems.

Unit 4 covers related rates, linear approximation, L'Hopital's rule, and interpreting the derivative in motion problems (position, velocity, acceleration).

What to prioritize: Related rates problems (draw the diagram, write the relationship, differentiate implicitly with respect to time), motion problems including switching between position, velocity and acceleration, and L'Hopital's rule for 0/0 and infinity/infinity forms.

Unit 5 is one of the heavier units. It covers the Mean Value Theorem and Extreme Value Theorem, first and second derivative tests, concavity and points of inflection, curve sketching, and optimization.

What to prioritize: The full workflow from f(x) to f'(x) to f''(x) with interpretation at each stage, optimization problems (define the constraint, express what you're maximizing/minimizing, differentiate, verify with the second derivative test), and being able to sketch f from a graph of f' or f''.

Unit 6 is the heaviest unit. It covers Riemann sums (left, right, midpoint, trapezoidal), definite and indefinite integrals, the Fundamental Theorem of Calculus, integration by u-substitution, and antiderivatives of standard functions.

What to prioritize: Fluency with u-substitution, using the FTC to evaluate definite integrals AND to differentiate integrals with variable upper limits, and Riemann sum interpretation (recognizing when a sum expresses an integral).

Unit 7 is the smallest weighting range. It covers slope fields, separable differential equations, and exponential growth and decay applications.

What to prioritize: Sketching slope fields from a given dy/dx, solving separable equations to find particular solutions given initial conditions, and setting up exponential growth/decay problems from a real-world description.

Unit 8 covers average value of a function, using accumulation to solve motion problems, area between curves, and volumes of solids of revolution (disk and washer methods) and cross sections.

What to prioritize: Area between two curves (sketch, identify intersections, integrate top minus bottom), the disk/washer method for volumes of revolution, and average value of a function over an interval.

If you're building a 10-week revision plan, a defensible weighting is roughly 2 weeks on Units 5, 6 and 8 combined, 1 week each on Units 1, 2, 3, 4 and 7, and the last 2 weeks on full timed past papers. The past papers are where FRQ setup fluency is built; the format has been stable for years and the rubric expectations are visible in released scoring guidelines.

AP Calc AB rewards students who show work clearly. On FRQs, a wrong final answer with correct setup, correct derivative and clear notation still earns the setup and process points; a right final answer with no work often earns fewer. Practice writing full solutions, not just computing.