Calculus II
College7 units and 62 lessons. Helio talks each one through and draws each step on a board.
Units
Areas and volumes
6 lessons- Area between curves expressed as functions of x and of ySketch a bounded region, choose a slice direction, and calculate its area with correct limits.
- Area between curves that intersect at more than two pointsFind crossings, calculate the area of every region, and justify a split-integral or absolute-value setup.
- Volumes with cross sections: squares, rectangles, triangles and semicirclesFind volume from a base region and the shape of its perpendicular cross sections.
- Volume with the disc method about axes and other linesFind a disc radius, set up its integral, and calculate volume about a horizontal or vertical line.
- Volume with the washer method about axes and other linesDraw both radii, set up washer integrals, and calculate volumes about horizontal or vertical lines.
- Volumes by cylindrical shellsBuild V = 2π ∫ (radius)(height) dx from one thin strip, then use it about the y-axis and about other vertical lines, checking against washers.
Techniques of integration
10 lessons- Integrating using integration by partsChoose and apply integration by parts to products, including repeated and cyclic cases.
- Trigonometric integralsIntegrate products of powers of sine and cosine, powers of tangent and secant, and products like sin 3x cos x by choosing the right identity.
- Trigonometric substitutionRemove a square root of a² − x², a² + x² or x² − a² with a trigonometric substitution, integrate, and return to x or convert the limits.
- Integrating using linear partial fractionsDecompose rational functions with distinct linear factors, then find indefinite and definite integrals.
- Partial fractions: repeated and quadratic factorsDecompose any rational function with repeated linear or irreducible quadratic factors, and integrate it into logarithms, powers and arctangents.
- Selecting techniques for antidifferentiation (BC)Choose a method, find an antiderivative, and check it by differentiating.
- Integration strategy: choosing a techniqueChoose a first move for any integral by asking a fixed order of questions, and recognise when no technique can give a formula.
- Numerical integration: trapezoid, midpoint and Simpson's rule with error boundsEstimate a definite integral from a table of values with three rules, predict whether each is high or low, and choose n to guarantee a tolerance.
- Evaluating improper integralsEvaluate an improper integral by writing its defining limit and deciding whether that limit is finite.
- Improper integrals: comparison and mixed typesDecide whether an improper integral converges, split it when it has two troubles, and use p-integrals and the comparison theorem when no antiderivative is handy.
Further applications of integration
5 lessons- The arc length of a smooth planar curve and distance travelledFind distance along a curve using an arc-length integral, and count every pass along a path.
- Surface area of a solid of revolutionDerive S = 2π ∫ (radius) ds from thin frustum bands and use it about the x-axis and the y-axis on curves where the integral simplifies.
- Work done by a variable forceCompute work as W = ∫ F dx for a hanging rope, a spring and a tank of water, slicing the load by distance.
- Hydrostatic pressure and forceFind the force of a still fluid on a flat plate by slicing it into horizontal strips with depth and width written as functions of y.
- Moments, centres of mass and centroidsFind balance points of point masses and centroids of uniform regions with x̄ = (1/A) ∫ x f dx and ȳ = (1/A) ∫ ½ f² dx, then use Pappus to check volumes.
Differential equations
8 lessons- Modelling situations with differential equations and verifying solutionsTranslate a rate description into a differential equation, verify a function, and use a condition to choose a solution.
- Sketching and reasoning with slope fieldsSketch slope segments, trace a solution through a given point, and recognize patterns and equilibria.
- Approximating solutions using Euler's methodEstimate a solution with Euler’s method and justify whether the estimate is above or below the actual value.
- General and particular solutions by separation of variablesFind a general solution, use an initial condition to select a particular solution, and state its largest domain.
- Exponential models with differential equationsSolve proportional-rate equations, use half-life or doubling time, and interpret a nonzero baseline.
- First-order linear equations and integrating factorsSolve y' + P(x) y = Q(x) by the integrating factor, with the constant in the right place, and fit an initial condition.
- Modelling with first-order equations: cooling, mixing and orthogonal trajectoriesTurn a cooling story, a mixing tank (fixed or changing volume) and a family of curves into first-order equations, solve them and check the results.
- Logistic models with differential equationsFind a logistic model’s limit, fastest-growth population, and solution from an initial value.
Parametric equations and polar coordinates
10 lessons- Parametric equations: graphing, direction and eliminating the parameterGraph a parametric path with arrows, eliminate t, and keep only the points reached.
- Polar coordinates and polar graphsPlot polar points and curves, convert coordinates, and recognize circles, cardioids, and roses.
- Defining and differentiating parametric equationsLocate points, find slopes and tangent lines, and identify horizontal and vertical tangencies.
- Second derivatives of parametric equationsCalculate d²y/dx² and use its sign to determine concavity at a given parameter value.
- Arc lengths of curves given by parametric equationsFind distance traveled along a parametric path, including when it retraces itself.
- Areas and surface areas for parametric curvesFind the area under a parametric curve and the surface area of a curve spun about an axis, with the right limits and sign.
- Polar coordinates and differentiating in polar formFind a polar curve’s tangent slope and tell whether its point moves toward or away from the origin.
- Area of a polar region and between two polar curvesCalculate polar area by choosing angles that trace a region once and, when needed, subtracting inner sectors.
- Arc length in polar coordinatesDerive and use L = ∫ √(r² + (dr/dθ)²) dθ, choosing one trace of the curve and keeping the absolute value.
- Conic sections in polar formRead e, d, the directrix, the vertices and the shape of a conic from r = ed/(1 ± e cos θ) or (1 ± e sin θ), and use it for an orbit.
Hyperbolic functions and complex exponentials
3 lessons- Hyperbolic functionsDefine cosh x and sinh x from the exponentials, graph them, show cosh²x − sinh²x = 1 as the hyperbola they trace, and use cosh to describe a hanging cable.
- Calculus of hyperbolic functionsDifferentiate and integrate sinh, cosh and tanh, write the inverse hyperbolic functions as logarithms, and evaluate ∫ dx/√(x² + 1) = sinh⁻¹ x + C.
- Complex numbers and Euler's formulaWrite a complex number as a point and as r e^{iθ}, prove e^{iθ} = cos θ + i sin θ from the Taylor series, and use it to multiply by rotating and scaling and to raise to powers.
Sequences and series
20 lessons- Sequences: limits and monotone convergenceFind a sequence's limit with the function trick and the landmark limits, and prove a recursive sequence converges before solving for its limit.
- Defining convergent and divergent infinite seriesDetermine convergence from partial sums and find a series’ sum when it exists.
- Working with geometric seriesDetermine whether a geometric series converges and find its sum when it does.
- Telescoping series and sums by partial fractionsFind the sum of a telescoping series by writing its partial sum, counting the leftover terms and taking the limit, and spot when it diverges.
- The nth term test for divergenceUse a term limit to prove divergence or recognize when the test gives no conclusion.
- The integral test, the harmonic series and p-seriesCheck integral-test conditions and use an improper integral or the p-series rule to classify a series.
- Comparison tests for convergenceChoose a known series and justify convergence or divergence by direct or limit comparison.
- Alternating series test for convergenceJustify convergence with both alternating series test conditions, and recognize when the nth-term test proves divergence.
- Alternating series error boundBound the error of an alternating-series approximation and determine whether it is high or low.
- Absolute or conditional convergenceClassify a series as absolutely convergent, conditionally convergent, or divergent, justifying both relevant tests.
- Ratio test for convergenceCompute consecutive-term ratio limits, apply the ratio test, and recognize when it is inconclusive.
- The root test and choosing a convergence testUse the root test on n-th powers and choose a first test for any series by asking seven questions in order.
- Radius and interval of convergence of power seriesFind a power series’ radius and justify its full interval by testing both endpoints.
- Power series: radius and interval of convergence in depthFind the radius and the exact interval of convergence of a power series, testing both endpoints, and say what termwise calculus does to each.
- Representing functions as power seriesBuild power series from a geometric series and determine where the resulting series converge.
- Finding Taylor polynomial approximations of functionsConstruct a Taylor polynomial from derivatives at its center and use it to approximate a nearby value.
- Lagrange error boundCalculate a Taylor polynomial error bound and use it to certify accuracy.
- Finding Taylor or Maclaurin series for a functionWrite first terms and a general term, then recover derivatives from coefficients.
- The binomial seriesWrite the series of (1 + x)ᵏ for any real k, find its first terms from derivatives, state where it is valid, and use it to approximate roots and build new series.
- Taylor series in use: limits, integrals and error controlUse known Maclaurin series to find limits, integrate functions with no elementary antiderivative, sum numerical series, and choose the right error bound for a stated tolerance.
