November 2014

Calculus

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6.1
  • Informal ideas of limit and convergence.
  • Limit notation.
  • Definition of derivative from first principles as
  • Derivative interpreted as gradient function and as rate of change.
  • Tangents and normals, and their equations.

Not required:

  • analytic methods of calculating limits.

Example: 0.3, 0.33, 0.333, ... converges to 1/3
.Technology should be used to explore ideas of limits, numerically and graphically.

Example:

  • Links to 1.1, infinite geometric series; 2.5–2.7, rational and exponential functions, and asymptotes.
  • Use of this definition for derivatives of simple polynomial functions only.
  • Technology could be used to illustrate other derivatives.

Link to 1.3, binomial theorem.

  • Use of both forms of notation, 
  • for the first derivative.
  • Identifying intervals on which functions are increasing or decreasing.
  • Use of both analytic approaches and technology.
  • Technology can be used to explore graphs and their derivatives.
  • Appl: Economics 1.5 (marginal cost, marginal revenue, marginal profit).
  • Appl: Chemistry 11.3.4 (interpreting the gradient of a curve).
  • Aim 8: The debate over whether Newton or Leibnitz discovered certain calculus concepts.
  • TOK: What value does the knowledge of limits have? Is infinitesimal behaviour applicable to real life?
  • TOK: Opportunities for discussing hypothesis formation and testing, and then the formal proof can be tackled by comparing certain cases, through an investigative approach.
6.2
  • Derivative of ex and ln x .
  • Differentiation of a sum and a real multiple of these functions.
  • The chain rule for composite functions.
  • The product and quotient rules.
  • The second derivative.
  • Extension to higher derivatives.
  • Link to 2.1, composition of functions.
  • Technology may be used to investigate the chain rule.
  • Use of both forms of notation,
 
6.3
  • Local maximum and minimum points. Testing for maximum or minimum.
  • Points of inflexion with zero and non-zero gradients.
  • Graphical behaviour of functions, including the relationship between the graphs of f , f ′ and f ′′ .
  • Optimization.
  • Applications.

Not required:

  • points of inflexion where f ′′(x) is not defined: for example, y = x13 at (0,0).
  • Using change of sign of the first derivative and using sign of the second derivative.
  • Use of the terms “concave-up” for f ′′(x) > 0 ,and “concave-down” for f ′′(x) < 0 .
  • At a point of inflexion , f ′′(x) = 0 and changes sign (concavity change).
  • f ′′(x) = 0 is not a sufficient condition for a point of inflexion: for example, y = x4 at (0,0) .
  • Both “global” (for large |x| ) and “local” behaviour.
  • Technology can display the graph of a derivative without explicitly finding an expression for the derivative.
  • Use of the first or second derivative test to justify maximum and/or minimum values.
  • Examples include profit, area, volume.
  • Link to 2.2, graphing functions.
Appl: profit, area, volume.
6.4
  • Indefinite integration as anti-differentiation.
  • Indefinite integral of
  • The composites of any of these with the linear function ax + b .
  • Integration by inspection, or substitution of the form ∫ f (g(x))g '(x)dx .
. .
6.5
  • Anti-differentiation with a boundary condition to determine the constant term.
  • Definite integrals, both analytically and using technology.
  • Areas under curves (between the curve and the x-axis).
  • Areas between curves.
  • Volumes of revolution about the x-axis.
  • The value of some definite integrals can only be found using technology.
  • Students are expected to first write a correct expression before calculating the area.
  • Technology may be used to enhance understanding of area and volume.
  • Int: Successful calculation of the volume of the pyramidal frustum by ancient Egyptians (Egyptian Moscow papyrus).
  • Use of infinitesimals by Greek geometers.
  • Accurate calculation of the volume of a cylinder by Chinese mathematician Liu Hui
  • Int: Ibn Al Haytham: first mathematician to calculate the integral of a function, in order to find the volume of a paraboloid.
6.6
  • Kinematic problems involving displacement s, velocity v and acceleration a.
  • Total distance travelled.
Appl: Physics 2.1 (kinematics).

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Statistics and probability

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5.1
  • Concepts of population, sample, random sample, discrete and continuous data.
  • Presentation of data: frequency distributions (tables); frequency histograms with equal class intervals;
  • box-and-whisker plots; outliers.
  • Grouped data: use of mid-interval values for calculations; interval width; upper and lower interval boundaries; modal class.

Not required:

  • frequency density histograms.
  • Continuous and discrete data.
  • Outlier is defined as more than 1.5 × IQR from the nearest quartile.
  • Technology may be used to produce histograms and box-and-whisker plots.
  • Appl: Psychology: descriptive statistics, random sample (various places in the guide).
  • Aim 8: Misleading statistics.
  • Int: The St Petersburg paradox, Chebychev, Pavlovsky.
5.2
  • Statistical measures and their interpretations.
  • Central tendency: mean, median, mode.
  • Quartiles, percentiles.
  • Dispersion: range, interquartile range, variance, standard deviation.
  • Effect of constant changes to the original data.
  • Applications.
  • On examination papers, data will be treated as the population.
  • Calculation of mean using formula and technology. Students should use mid-interval values to estimate the mean of grouped data.
  • Calculation of standard deviation/variance using only technology.

Link to 2.3, transformations.
Examples:

  • If 5 is subtracted from all the data items, then the mean is decreased by 5, but the standard deviation is unchanged.
  • If all the data items are doubled, the median is doubled, but the variance is increased by a factor of 4.
  • Appl: Psychology: descriptive statistics (various places in the guide).
  • Appl: Statistical calculations to show patterns and changes; geographic skills; statistical graphs.
  • Appl: Biology 1.1.2 (calculating mean and standard deviation ); Biology 1.1.4 (comparing means and spreads between two or more samples).
  • Int: Discussion of the different formulae for variance.
  • TOK: Do different measures of central tendency express different properties of the data? Are these measures invented or discovered? Could mathematics make alternative, equally true, formulae? What does this tell us about mathematical truths?
  • TOK: How easy is it to lie with statistics?
5.3 Cumulative frequency; cumulative frequency graphs; use to find median, quartiles, percentiles. Values of the median and quartiles produced by technology may be different from those obtained from a cumulative frequency graph. .
5.4
  • Linear correlation of bivariate data.
  • Pearson’s product–moment correlation coefficient r.
  • Scatter diagrams; lines of best fit.
  • Equation of the regression line of y on x.
  • Use of the equation for prediction purposes.
  • Mathematical and contextual interpretation.

Not required:

  • the coefficient of determination R2.
  • Independent variable x, dependent variable y.
  • Technology should be used to calculate r. However, hand calculations of r may enhance understanding.
  • Positive, zero, negative; strong, weak, no correlation.
  • The line of best fit passes through the mean point.
  • Technology should be used find the equation.
  • Interpolation, extrapolation.
  • Appl: Chemistry 11.3.3 (curves of best fit).
  • Appl: Geography (geographic skills). Measures of correlation; geographic skills.
  • Appl: Biology 1.1.6 (correlation does not imply causation).
  • TOK: Can we predict the value of x from y, using this equation?
  • TOK: Can all data be modelled by a (known) mathematical function? Consider the reliability and validity of mathematical models in describing real-life phenomena.
5.5
  • Concepts of trial, outcome, equally likely outcomes, sample space (U) and event.
  • The probability of an event
  • The complementary events A and A′ (not A).
  • Use of Venn diagrams, tree diagrams and tables of outcomes.
  • The sample space can be represented diagrammatically in many ways.
  • Experiments using coins, dice, cards and so on, can enhance understanding of the distinction between (experimental) relative frequency and (theoretical) probability.
  • Simulations may be used to enhance this topic.
  • Links to 5.1, frequency; 5.3, cumulative frequency.
TOK: To what extent does mathematics offer models of real life? Is there always a function to model data behaviour?
5.6
  • Combined events, P(A∪ B).
  • Mutually exclusive events: P(A∩ B) = 0 .Conditional probability; the definition
  • Independent events; the definition P( A| B) = P(A) = P( A| B′)  .
  • Probabilities with and without replacement.
  • The non-exclusivity of “or”.
  • Problems are often best solved with the aid of a Venn diagram or tree diagram, without explicit use of formulae.
  • Aim 8: The gambling issue: use of probability in casinos. Could or should mathematics help increase incomes in gambling?
  • TOK: Is mathematics useful to measure risks?
  • TOK: Can gambling be considered as an application of mathematics? (This is a good opportunity to generate a debate on the nature, role and ethics of mathematics regarding its applications.)
5.7
  • Concept of discrete random variables and their probability distributions.
  • Expected value (mean), E(X ) for discrete data.
  • Applications.
  • Simple examples only, such as:
  • E(X ) = 0 indicates a fair game where X represents the gain of one of the players.
  • Examples include games of chance.
.
5.8
  • Binomial distribution.
  • Mean and variance of the binomial distribution.

Not required:

  • formal proof of mean and variance.
Link to 1.3, binomial theorem.
  • Conditions under which random variables have this distribution.
  • Technology is usually the best way of calculating binomial probabilities.
.
5.9
  • Normal distributions and curves.
  • Standardization of normal variables (z-values, z-scores).
  • Properties of the normal distribution.
  • Probabilities and values of the variable must be found using technology.
  • Link to 2.3, transformations.
  • The standardized value ( z ) gives the number of standard deviations from the mean.
  • Appl: Biology 1.1.3 (links to normal distribution).
  • Appl: Psychology: descriptive statistics (various places in the guide).

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Vectors

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4.1
  • Vectors as displacements in the plane and in three dimensions.
  • Components of a vector; column  representation;

Algebraic and geometric approaches to the following:

  • the sum and difference of two vectors; the zero vector, the vector −v ;
  • multiplication by a scalar, kv ; parallel vectors;
  • magnitude of a vector, |v| ;
  • unit vectors; base vectors; i, j and k;
  • position vectors 
  • Link to three-dimensional geometry, x, y and z- axes.
  • Components are with respect to the unit vectors i, j and k (standard basis).
  • Applications to simple geometric figures are essential.
  • The difference of v and w is v − w = v + (−w) . Vector sums and differences can be represented by the diagonals of a parallelogram.
  • Multiplication by a scalar can be illustrated by enlargement.
  • Distance between points A and B is the magnitude of 
  • Appl: Physics 1.3.2 (vector sums and differences) Physics 2.2.2, 2.2.3 (vector resultants).
  • TOK: How do we relate a theory to the author? Who developed vector analysis: JW Gibbs or O Heaviside?
4.2
  • The scalar product of two vectors.
  • Perpendicular vectors; parallel vectors.
  • The angle between two vectors.
  • The scalar product is also known as the “dot product”.
  • Link to 3.6, cosine rule.
  • For non-zero vectors, v w = 0 is equivalent to the vectors being perpendicular For parallel vectors, w = kv , |v ⋅w| = |v| |w| .
 
4.3 Vector equation of a line in two and three dimensions: r = a + tb .
  • Relevance of a (position) and b (direction).
  • Interpretation of t as time and b as velocity, with |b| representing speed.
  • Aim 8: Vector theory is used for tracking displacement of objects, including for peaceful and harmful purposes.
  • TOK: Are algebra and geometry two separate domains of knowledge? (Vector algebra is a good opportunity to discuss how geometrical properties are described and generalized by algebraic methods.)
4.4
  • Distinguishing between coincident and parallel lines.
  • Finding the point of intersection of two lines.
  • Determining whether two lines intersect.
. .

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Students will use algebraic functions on a coordinate grid to create a work of math art. Students will be expected to use at 10 different “curves” including at least 3 different types of functions. Students will identify the different curves by equation, give the domain and range for that curve, and describe how the curve used has been transformed from the parent function for that type of curve.

Students and their partners will choose cities to compare the periodic behavior of their daylight and temperatures. While hours of daylight is perfectly periodic and predictable each year, temperatures are more erratic and curves will be based on averages. Students will identify the unique geographical characteristics of their cities that determine their hours of daylight and influence their temperatures. Students will then observe how these differences are revealed in the sinusoidal equations for their data.

Students will choose a quantitative variable on which they will obtain two comparable sets of data. (For example, wins for the Dallas Mavericks versus wins for the San Antonio Spurs over the last 25 seasons.) Students will obtain the data and analyze its type and whether it’s random or representative. Students will then create graphical displays to help convey the concept of shape of a distribution. Then students will then move into the numerical analysis of center and spread and include a written comparison of these characteristics for the two data sets.

Circular functions and trigonometry

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3.1 The circle: radian measure of angles; length of an arc; area of a sector. Radian measure may be expressed as exact multiples of π , or decimals.
  • Int: Seki Takakazu calculating π to ten decimal places.
  • Int: Hipparchus, Menelaus and Ptolemy.
  • Int: Why are there 360 degrees in a complete turn? Links to Babylonian mathematics.
  • TOK: Which is a better measure of angle: radian or degree? What are the “best” criteria by which to decide?
  • TOK: Euclid’s axioms as the building blocks of Euclidean geometry. Link to non-Euclidean geometry.
3.2
  • Definition of cosθ and sinθ  in terms of the unit circle.
  • Definition of
  • Exact values of trigonometric ratios of  and their multiples.
  • The equation of a straight line through the origin is y = x tanθ
  • Examples:
  • Aim 8: Who really invented “Pythagoras’ theorem”?
  • Int: The first work to refer explicitly to the sine as a function of an angle is the Aryabhatiya of Aryabhata (ca. 510).
  • TOK: Trigonometry was developed by successive civilizations and cultures. How is mathematical knowledge considered from a sociocultural perspective?
3.3
  • The Pythagorean identity cos2 θ + sin2 θ = 1.Double angle identities for sine and cosine.
  • Relationship between trigonometric ratios.
  • Simple geometrical diagrams and/or technology may be used to illustrate the double angle formulae (and other trigonometric identities).

Examples:

  • Given sinθ , finding possible values of tanθ without finding θ .
  • Given  and x is acute, find sin2x without finding x.
.
3.4
  • The circular functions sin x , cos x and tan x : their domains and ranges; amplitude, their periodic nature; and their graphs.
  • Composite functions of the form f (x) = asin (b(x + c) ) + d .
  • Transformations.
  • Applications.
  • Examples:
  • Example: y = sinx used to obtain y = 3sin2x by a stretch of scale factor 3 in the y-direction and a stretch of scale factor 1/2 in the x-direction.
  • Link to 2.3, transformation of graphs.
  • Examples include height of tide, motion of a Ferris wheel.
Appl: Physics 4.2 (simple harmonic motion).
3.5
  • Solving trigonometric equations in a finite interval, both graphically and analytically.
  • Equations leading to quadratic equations in sin x, cos x or tan x

. Not required:

  • the general solution of trigonometric equations.
 
3.6
  • Solution of triangles.
  • The cosine rule.
  • The sine rule, including the ambiguous case.
  • Area of a triangle, 
  • Applications.
  • Pythagoras’ theorem is a special case of the cosine rule.
  • Link with 4.2, scalar product, noting that:
  • Examples include navigation, problems in two and three dimensions, including angles of elevation and depression.
  • Aim 8: Attributing the origin of a mathematical discovery to the wrong mathematician.
  • Int: Cosine rule: Al-Kashi and Pythagoras.
  • TOK: Non-Euclidean geometry: angle sum on a globe greater than 180°.

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