Booklet 0.2 Formula List of Applications and Interpretation Higher Level for IBDP Mathematics λ Intensive Notes by Topics here IBDP Maths Info. & Exam Tricks here Exam & GDC Skills Video List here More Mock Papers & Marking Service here 1 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics 1 Standard Form Standard Form: A number in the form ()a 10k , where 1 a 10 and k is an integer 2 Approximation and Error Summary of rounding methods: 2.71828 Correct to 3 significant figures Correct to 3 decimal places Round off 2.72 2.718 Consider a quantity measured as Q and correct to the nearest unit d : 1 d : Maximum absolute error 2 1 1 Q d A Q d : Range of the actual value A 2 2 1 Q d : Lower bound (Least possible value) of A 2 1 Q d : Upper bound of A 2 Maximum absolute error 100% : Percentage error Q 2 SE Production Limited 3 Functions The function y f ( x) : 1. f (a) : Functional value when x a 2. 3. Domain: Set of values of x Range: Set of values of y Properties of rational function y 1. 2. 3. ax b : cx d 1 : Reciprocal function x a y : Horizontal asymptote c d x : Vertical asymptote c y f g ( x) f ( g ( x)) : Composite function when g ( x) is substituted into f ( x) Steps of finding the inverse function y f 1 ( x) of f ( x) : 1. Start from expressing y in terms of x 2. Interchange x and y 3. Make y the subject in terms of x Properties of y f 1 ( x) : 1. f ( f 1 ( x)) f 1 ( f ( x)) x 2. The graph of y f 1 ( x) is the reflection of the graph of y f ( x) about yx f 1 ( x) exists only when f ( x) is one-to-one in the restricted domain 3 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics Summary of transformations: f ( x) f ( x) k : Translate upward by k units f ( x) f ( x) k : Translate downward by k units f ( x) f ( x h) : Translate to the left by h units f ( x) f ( x h) : Translate to the right by h units f ( x) kf ( x) : Vertical stretch of scale factor k f ( x) f (kx) : kf ( x) f ( x) f (kx) x Horizontal compression of scale factor k f ( x) f ( x ) : Reflection about the x -axis f ( x ) f ( x) : Reflection about the y -axis Variations: 1. y kx, k 0 : y is directly proportional to x 2. y k , k 0 : y is inversely proportional to x x 4 SE Production Limited 4 Quadratic Functions General form y ax 2 bx c , where a 0 : a0 The graph opens upward a0 The graph opens downward c y -intercept h b 2a k ah2 bh c xh x -coordinate of the vertex y -coordinate of the vertex Extreme value of y Equation of the axis of symmetry Other forms: 1. y a( x h)2 k : Vertex form 2. y a( x p)( x q) : Factored form with x -intercepts p and q b pq 2a 2 h The x -intercepts of the quadratic function y ax 2 bx c are the roots of the corresponding quadratic equation ax2 bx c 0 5 Exponential and Logarithmic Functions y a x : Exponential function, where a 1 y log a x : Logarithmic function, where a 0 y log x log10 x : Common Logarithmic function y ln x log e x : Natural Logarithmic function, where e 2.71828... is an exponential number 5 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics Properties of the graphs of y = a x : a >1 0 < a <1 y -intercept = 1 y increases as x increases y decreases as x increases y tends to zero as x tends to y tends to zero as x tends to negative infinity positive infinity Horizontal asymptote: y = 0 Laws of logarithm, where a , b , c , p , q , x > 0 : 1. x = a y ⇔ y = log a x 2. log a 1 = 0 3. log a a = 1 4. log a p + log a q = log a pq 5. p log a p − log a q = log a q 6. log a p n = n log a p 7. log b a = f ( x) = L : Logistic function, where L , C and k are positive constants 1 + Ce − kx Semi-log model: log c a log c b 1. y =k ⋅ a x ⇔ ln y =(ln a ) x + ln k : Semi-log model 2. ln a : Gradient of the straight line graph on ln y -x plane 3. ln k : Vertical intercept of the straight line graph on ln y -x plane Log-log models: 1. y =k ⋅ x n ⇔ ln y =n ln x + ln k : Log-log model 2. n : Gradient of the straight line graph on ln y - ln x plane 3. ln k : Vertical intercept of the straight line graph on ln y - ln x plane 6 SE Production Limited 6 Systems of Equations ax by c : 2 2 system dx ey f ax by cz d ex fy gz h : 3 3 system ix jy kz l The above systems can be solved by PlySmlt2 in TI-84 Plus CE 7 Arithmetic Sequences Properties of an arithmetic sequence un : 1. u1 : First term 2. d u2 u1 un un1 : Common difference 3. un u1 (n 1)d : General term ( n th term) 4. Sn n u u u u r 1 8 n n 2u1 (n 1)d u1 un : The sum of the first n terms 2 2 r 1 2 3 un 1 un : Summation sign Geometric Sequences Properties of a geometric sequence un : 1. u1 : First term 2. r u2 u1 un un1 : Common ratio 3. un u1 r n1 : General term ( n th term) 4. Sn u1 (1 r n ) : The sum of the first n terms 1 r 7 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics S 9 u1 : The sum to infinity of a geometric sequence un , given that 1 r 1 1 r Financial Mathematics Compound Interest: PV : Present value r % : Interest rate per annum (per year) n : Number of years k : Number of compounded periods in one year kn r FV PV 1 : Future value 100k I FV PV : Interest Inflation: i % : Inflation rate R% : Interest rate compounded yearly ( R i)% : Real rate Annuity: 1. Payments at the beginning of each year 2. Payments at the end of each year Amortization: 1. Payments at the beginning of each year 2. Payments at the end of each year 8 SE Production Limited 10 Coordinate Geometry Consider the points P( x1 , y1 ) and Q( x2 , y2 ) on a x - y plane: y2 y1 : Slope of PQ x2 x1 1. m 2. d ( x2 x1 )2 ( y2 y1 )2 : Distance between P and Q 3. x1 x2 y1 y2 : Mid-point of PQ , 2 2 Consider the points P( x1 , y1 , z1 ) and Q( x2 , y2 , z2 ) on a x - y - z plane: 1. z -axis: The axis perpendicular to the x - y plane 2. d ( x2 x1 )2 ( y2 y1 )2 ( z2 z1 )2 : Distance between P and Q 3. x1 x2 y1 y2 z1 z2 : Mid-point of PQ , , 2 2 2 Forms of straight lines with slope m and y -intercept c : 1. y mx c : Slope-intercept form 2. Ax By C 0 : General form Ways to find the x -intercept and the y -intercept of a line: 1. Substitute y 0 and make x the subject to find the x -intercept 2. Substitute x 0 and make y the subject to find the y -intercept 11 Voronoi Diagrams Elements in Voronoi Diagrams: Site: A given point Cell of a site: A collection of points which is closer to the site than other sites Boundary: A line dividing the cells Vertex: An intersection of boundaries Related problems: 1. Nearest neighbor interpolation 2. 3. Incremental algorithm Toxic waste dump problem 9 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics 12 Trigonometry Consider a right-angled triangle ABC : AB2 BC2 AC2 : Pythagoras’ Theorem AB sin AC BC : Trigonometric ratios cos AC AB tan BC Properties of a general trigonometric function y A sin B( x C ) D : 1. 2. 3. 4. A ymax ymin : Amplitude 2 360 2 or Period Period y ymin D max 2 C can be found by substitution of a point on the graph B Properties of graphs of trigonometric functions: 1. 2. Amplitude 1 3. 1 sin x 1 1. 2. Amplitude 1 3. 1 cos x 1 10 SE Production Limited Period 360 or 2 Period 360 or 2 Trigonometric identities: sin 1. tan cos 2 2. sin cos2 1 ASTC diagram y S (90 180) sin 0 sin 0 cos 0 cos 0 tan 0 tan 0 T (180 270) sin 0 C (270 360) cos 0 cos 0 tan 0 tan 0 A (0 90) x sin 0 13 2-D Trigonometry Consider a triangle ABC : 1. sin A sin B a b or : Sine rule sin A sin B a b 2. a2 b2 c2 2bc cos A 3. b2 c 2 a 2 or cos A : Cosine rule 2bc 1 ab sin C : Area of the triangle ABC 2 Consider a sector OPRQ with centre O , radius r and POQ : 2 r r2 r2 360 360 : Arc length PRQ : Area of the sector OPRQ 1 r 2 sin : Area of the segment PRQ 360 2 11 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics Consider a triangle ABC : sin A sin B a b or : Sine rule sin A sin B a b Note: The ambiguous case exists if two sides and an angle are known, and the angle is opposite to the shorter known side x y rad : Method of conversions between degree and radian 180 rad Consider a sector OPRQ with centre O , radius r and POQ in radian: 1. r : Arc length PQ 2. 1 2 r : Area of the sector OPRQ 2 1 2 r ( sin ) : Area of the segment PRQ 2 3. 14 Areas and Volumes For a cube of side length l : 1. 6l 2 : Total surface area 2. l 3 : Volume For a cuboid of side lengths a , b and c : 1. 2(ab bc ac) : Total surface area 2. For a prism of height h and cross-sectional area A : 1. abc : Volume Ah : Volume For a cylinder of height h and radius r : 1. 2 r 2 2 rh : Total surface area 2. 2 rh : Lateral surface area 3. r 2 h : Volume 12 SE Production Limited For a pyramid of height h and base area A : 1 1. Ah : Volume 3 For a circular cone of height h and radius r : 1. l r 2 h2 : Slant height 2. r 2 rl : Total surface area rl : Curved surface area 3. 4. 1 2 r h : Volume 3 For a sphere of radius r : 1. 4 r 2 : Total surface area 2. 4 3 r : Volume 3 For a hemisphere of radius r : 1. 3 r 2 : Total surface area 2. 2 r 2 : Curved surface area 3. 2 3 r : Volume 3 15 Complex Numbers Terminologies of complex numbers: i 1 : Imaginary unit z a bi : Complex number in Cartesian form a : Real part of z b : Imaginary part of z z* a bi : Conjugate of z a bi z r a 2 b2 : Modulus of z a bi arg( z ) arctan b : Argument of z a bi a 13 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics Properties of Argand diagram: 1. Real axis: Horizontal axis 2. Imaginary axis: Vertical axis Forms of complex numbers: 1. z a bi : Cartesian form 2. z r (cos isin ) rcis : Modulus-argument form 3. z rei : Euler form Properties of moduli and arguments of complex numbers z1 and z2 : 1. z1 z2 z1 z2 2. z z1 1 z2 z2 3. arg( z1 z2 ) arg z1 arg z2 4. z arg 1 arg z1 arg z2 z2 If z a bi is a root of the polynomial equation p( z ) 0 , then z* a bi is also a root of p( z ) 0 14 SE Production Limited 16 Matrices Terminologies of matrices: a11 a A 21 am1 a12 a22 am 2 a1n a2 n : A m n matrix with m rows and n columns amn aij : Element on the i th row and the j th column 0 1 0 0 1 0 : Identity matrix I 1 0 0 0 0 0 0 0 0 : Zero matrix 0 0 0 0 0 a11 0 0 0 a22 : Diagonal matrix 0 ann 0 A det(A) : Determinant of A A is non-singular if det(A) 0 A 1 : Inverse of A A 1 exists if A is non-singular a b For any 2 2 square matrices A : c d 1. A det(A) ad bc : Determinant of A 2. A 1 1 d b : Inverse of A ad bc c a 15 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics Operations of matrices: b1n a11 b11 bmn am1 bm1 1. a11 a m1 a1n b11 amn bm1 2. a11 k a m1 a1n ka11 amn kam1 3. cij ai1b1 j ai 2b2 j a1n b1n amn bmn ka1n kamn ainbnj : The element on the i th row and the j th a1n b11 b1k a11 column of C AB , where A , B and C a amn bnk m1 bn1 are m n , n k and m k matrices respectively ax by c x A 2 2 system can be expressed as AX B , where X can be dx ey f y 1 a b c solved by X A B d e f 1 ax by cz d x A 3 3 system ex fy gz h can be expressed as AX B , where X y can ix jy kz l z a 1 be solved by X A B e i b f j c g k 1 d h l Eigenvalues and eigenvectors of A : 1. det(A I) : Characteristic polynomial of A 2. Solution(s) of det(A I) 0 : Eigenvalue(s) of A 3. v : Eigenvector of A corresponding to the eigenvalue , which satisfies Av v Diagonalization of A : 1. 1 0 0 2 D 0 0 0 0 : Diagonal matrix of the eigenvalues of A n 2. V v1 v n : A matrix of the eigenvectors of A 3. A VDV1 An VDn V 1 v2 16 SE Production Limited Two-dimensional transformation matrices: 1. 2. 3. 4. 5. 6. 7. 8. 9. 1 0 : Reflection about the x -axis 0 1 1 0 : Reflection about the y -axis 0 1 cos 2 sin 2 : Reflection about the line y mx , where m tan sin 2 cos 2 1 0 : Vertical stretch with scale factor k 0 k k 0 : Horizontal stretch with scale factor k 0 1 k 0 : Enlargement about the origin with scale factor k 0 k cos sin : Rotation with positive angle anticlockwise about the sin cos origin cos sin : Rotation with positive angle clockwise about the origin sin cos Area of the image det(T ) Area of the object, where T is the transformation matrix 17 Vectors Terminologies of vectors: AB : Vector of length AB with initial point A and terminal point B OP : Position vector of P , where O is the origin AB : Magnitude (length) of AB vˆ 1 v : Unit vector parallel to v , with vˆ 1 v 0 : Zero vector i : Unit vector along the positive x -axis j : Unit vector along the positive y -axis k : Unit vector along the positive z -axis 17 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics v1 A vector v can be expressed as v v1i v2 j v3k or v v2 v 3 Properties of vectors: 1. 3. u1 v1 u1 v1 u2 v2 u2 v2 u v u v 3 3 3 3 v and kv are in the same direction if k 0 4. v and kv are in opposite direction if k 0 5. v1 kv1 k v2 kv2 v kv 3 3 2. AB OB OA u1 v1 Properties of the scalar product u v of u u2 and v v2 where is the u v 3 3 angle between u and v : 1. u v u1v1 u2v2 u3v3 u v cos 2. i i j j k k 1 3. i j j k k i 0 4. u and v are in the same direction if u v u v 5. u and v are in opposite direction if u v u v 6. u and v are perpendicular if u v 0 7. u v v u 8. u u u 2 18 SE Production Limited u1 v1 Properties of the vector product u v of u u2 and v v2 where is the u v 3 3 angle between u and v : 2. u2v3 u3v2 u v u3v1 u1v3 u v sin nˆ , where nˆ //(u v) u v u v 1 2 2 1 i i j j k k 0 3. i j k , j k i and k i j 4. j i k , k j i and i k j 5. u and v are parallel if u v 0 6. u and v are perpendicular if u v u v 7. u v ( v u) 1. The area of the parallelogram with adjacent sides AB and AD is AB AD The area of the triangle with adjacent sides AB and AD is Forms of the straight line with fixed point A(a1 , a2 , a3 ) and direction vector 1 AB AD 2 b b1i b2 j b3k : 1. x a1 b1 y a2 t b2 , t z a b 3 3 2. x a1 b1t y a2 b2t : Parametric form z a b t 3 3 Vector components: 1. 2. uv : Vector component of u parallel to v v u v v : Vector component of u perpendicular to v 19 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics 18 Graph Theory Terminologies of graphs: Vertex: A point on a graph Edge: Arcs that connect vertices Walk: A sequence of edges Path: A sequence of edges that passes through any vertex and any edge at most once Degree of a vertex: Number of edges connecting the vertex Connected graph: A graph that there exists at least one walk between any two vertices Unconnected graph: A graph that there exist at least two vertices that there is no walk between them Subgraph of a graph: A collection of some edges and vertices of the original graph Loop: An edge that starts and ends at the same vertex Simple graph: A graph that has no loops and no multiple edges connecting the same pair of vertices Multiple graph: A graph that has multiple edges connecting at least one pair of vertices Cycle: A path that the starting vertex is the end vertex Tree: A connected graph with no cycles Spanning tree: A tree that connects all vertices in the graph Directed graphs: 1. 2. Directed graph: A graph that all edges are assigned with directions In-degree of a vertex: Number of edges connecting and pointing towards 3. the vertex Out-degree of a vertex: Number of edges connecting and pointing away from the vertex 20 SE Production Limited Adjacency matrix M of a graph with n vertices: 1. n n : Order of M 2. The entry mij 1 if there is an edge connecting the vertex i and the vertex j , and mij 0 if otherwise 3. 4. M p shows the number of walks of length p in the graph p M shows the number of walks of length less than or equal to p in the r r 1 graph 5. Algorithms of finding minimum spanning trees: 1. Kruskal’s algorithm 2. The column sum of a transition matrix of a directed graph must be equal to 1 Prim’s algorithm Eulerian trails and circuits: 1. 2. Trail: A sequence of edges that passes through any edge at most once Circuit: A trail that the starting vertex is the end vertex 3. 4. Eulerian trail: A trail that passes through all edges of a graph Eulerian circuit: A circuit that passes through all edges of a graph 5. An Eulerian trail exists if there exists two and only two vertices of odd degree 6. An Eulerian circuit exists if all vertices are of even degree 7. Chinese postman problem can be used to find the route of minimum weight that covers all edges of a graph Hamiltonian paths and cycles: 1. Complete graph: A graph that there exists an edge for any pair of two 2. vertices Hamiltonian path: A path that passes through all vertices of a graph 3. Hamiltonian cycle: A cycle that passes through all vertices of a graph Travelling Salesman problem: 1. Travelling Salesman problem can be used to find the cycle of minimum weight that passes through all vertices of a graph 2. Nearest neighbour algorithm can be used to find the upper bound of the solution of a travelling salesman problem 3. Deleted vertex algorithm can be used to find the lower bound of the solution of a travelling salesman problem 21 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics 19 Differentiation dy f ( x) : Derivative of the function y f ( x) (First derivative) dx Rules of differentiation: 1. f ( x) x n f ( x) nx n1 2. f ( x) p( x) q( x) f ( x) p( x) q( x) 3. f ( x) cp( x) f ( x) cp( x) Relationship between graph properties and the derivatives: 1. f ( x) 0 for a x b : f ( x) is increasing in the interval 2. f ( x) 0 for a x b : f ( x) is decreasing in the interval 3. f (a) 0 : (a, f (a)) is a stationary point of f ( x) 4. f (a) 0 and f ( x) changes from positive to negative at x a : (a, f (a)) is a maximum point of f ( x) 5. f (a) 0 and f ( x) changes from negative to positive at x a : (a, f (a)) is a minimum point of f ( x) Tangents and normals: 1. f (a) : Slope of tangent at x a 2. 3. 4. 1 : Slope of normal at x a f (a ) y f (a) f (a)( x a) : Equation of tangent at x a 1 y f (a ) ( x a) : Equation of normal at x a f (a) Derivatives of a function y f ( x) : 1. d 2 y d dy f ( x) : Second derivative dx 2 dx dx 2. dn y f ( n ) ( x) : n -th derivative n dx 22 SE Production Limited More rules of differentiation: f ( x) sin x f ( x) cos x f ( x) cos x f ( x) sin x 1 f ( x) tan x f ( x) cos 2 x f ( x) e x f ( x) e x f ( x) ln x f ( x) f ( x) p(q( x)) f ( x) p(q( x)) q( x) f ( x) p ( x) q ( x) f ( x) p( x)q( x) p( x)q( x) p( x) q( x) p( x)q( x) p( x)q( x) f ( x) (q( x)) 2 f ( x) 1 x f (a) 0 and f ( x) changes sign at x a : (a, f (a)) is a point of inflexion of f ( x) dN dN dx : Rate of change of N with respect to the time t dt dx dt Tests for optimization: 1. First derivative test 2. Second derivative test Applications in kinematics: 1. s(t ) : Displacement with respect to the time t 2. v(t ) s(t ) : Velocity 3. a(t ) v(t ) : Acceleration 20 Integration and Trapezoidal Rule Integrals of a function y f ( x) : 1. f ( x)dx : Indefinite integral of f ( x) 2. f ( x)dx : Definite integral of f ( x) from a to b b a 23 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics Rules of integration: 1 n +1 n 1. = ∫ x dx n + 1 x + C 2. ∫ ( p′( x) + q′( x))dx = p( x) + q( x) + C 3. x)dx cp ( x) + C ∫ cp′( = b ∫ f ( x)dx : Area under the graph of f ( x) and above the x -axis, between x = a a and x = b , where f ( x) ≥ 0 Trapezoidal Rule: a , b ( a < b ): End points n : Number of intervals h= b−a : Interval width n 1 b ∫ f ( x)dx can be estimated by 2 h [ f ( x ) + f ( x ) + 2( f ( x ) + f ( x ) + + f ( x ))] a 1 n 2 n −1 Estimation by Trapezoidal Rule: 1. The estimation overestimates if the estimated value is greater than the actual value of 2. b ∫ f ( x)dx a The estimation underestimates if the estimated value is less than the actual value of 0 b ∫ f ( x)dx a More rules of integration: − cos x + C ∫ sin xdx = ∫ e d=x e + C xdx sin x + C ∫ cos = dx ln x + C ∫ x= x x 1 1 dx tan x + C ∫ cos x= Integration by substitution 2 b b a a )dx [ f ( x= )] f (b) − f (a ) ∫ f ′( x= Areas on x - y plane, between x = a and x = b : 1. 2. b ∫ f ( x) dx : Area between the graph of f ( x) and the x -axis a b ∫ f ( x) − g ( x) dx : Area between the graph of f ( x) and the graph of g ( x) a 24 SE Production Limited Areas on x - y plane, between y c and y d : d 1. g ( y) dy : Area between the graph of g ( y) and the y -axis 2. g ( y) f ( y) dy : Area between the graph of g ( y) and the graph of f ( y) c d c Volumes of revolutions about the x -axis, between x a and x b : 1. b V ( f ( x))2 dx : Volume of revolution when the region between the a graph of f ( x) and the x -axis is rotated 360 about the x -axis 2. b V (( f ( x))2 ( g ( x))2 )dx : Volume of revolution when the region a between the graphs of f ( x) and g ( x) is rotated 360 about the x -axis Volumes of revolutions about the y -axis, between y c and y d : 1. d V ( g ( y))2 dy : Volume of revolution when the region between the c graph of g ( y) and the y -axis is rotated 360 about the y -axis 2. d V (( g ( y))2 ( f ( y ))2 )dy : Volume of revolution when the region c between the graphs of g ( y) and f ( y) is rotated 360 about the y -axis Applications in kinematics: 1. a(t ) : Acceleration with respect to the time t 2. v(t ) a(t )dt : Velocity 3. s(t ) v(t )dt : Displacement 4. d v(t ) dt : Total distance travelled between t1 and t 2 t2 t1 21 Differential Equations dy f ( x, y ) : First order differential equation dx Solving dy f ( x) g ( y ) by separating variables: dx dy 1 f ( x) g ( y ) dy f ( x)dx dx g ( y) 25 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics Coupled differential equations: 1. dx dx dt a b x dt ax by can be expressed as dy c d y dy cx dy dt dt 3. a b 1 , 2 : Eigenvalues of c d v1 , v 2 : Eigenvectors corresponding to 1 and 2 respectively 4. x Ae1t v1 Be2t v 2 : Solution of the system 5. Stable equilibrium if 1 , 2 0 or 1 a bi , 2 a bi and a 0 6. Unstable equilibrium if 1 , 2 0 or 1 a bi , 2 a bi and a 0 7. Saddle point if 12 0 2. dy f ( x, y ) by Euler’s method, with ( x0 , y0 ) and step length h : dx xn 1 xn h y y h dy n n 1 dx ( xn , yn ) Solving dx dt ax by Solving by Euler’s method, with (t0 , x0 , y0 ) and step length h : dy cx dy dt dx xn 1 xn h dt ( tn , xn , yn ) tn1 tn h and y y h dy n n 1 dt (tn , xn , yn ) Predator-prey models: dx dt (a by ) x , where a , b , c and d are positive constants dy (cx d ) y dt 26 SE Production Limited The second-order differential equation d2 x dx a bx 0 can be expressed as 2 dt dt dv dt av bx dx v dt 22 Statistics Relationship between frequencies and cumulative frequencies: Data Frequency 10 20 30 f1 f2 f3 Data less than or equal to 10 20 30 Measures of central tendency for a data set {x1 , x2 , x3 , Cumulative frequency f1 f1 f 2 f1 f 2 f3 , xn } arranged in ascending order: x x x3 xn 1. : Mean x 1 2 n 2. The datum or the average value of two data at the middle: Median 3. The datum appears the most: Mode Measures of dispersion for a data set {x1 , x2 , x3 , , xn } arranged in ascending order: 1. xn x1 : Range 2. Two subgroups A and B can be formed from the data set such that all data of the subgroup A are less than or equal to the median, while all data of the subgroup B are greater than or equal to the median 3. Q1 The median of the subgroup A: Lower quartile 4. Q3 The median of the subgroup B: Upper quartile 5. Q3 Q1 : Inter-quartile range (IQR) 6. ( x1 x )2 ( x2 x )2 ( x3 x )2 n ( xn x ) 2 : Standard deviation 27 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics Box-and-whisker diagram: A datum x is defined to be an outlier if x Q1 1.5IQR or x Q3 1.5IQR Coding of data: 1. Only the mean, the median, the mode and the quartiles will change when each datum of the data set is added or subtracted by a value 2. All measures of central tendency and measures of dispersion will change when each datum of the data set is multiplied or divided by a value 23 Probability Terminologies: 1. U : Universal set 2. A : Event 3. 4. x : Outcome of an event n(U ) : Total number of elements 5. n( A) : Number of elements in A Formulae for probability: 1. P( A B) P( A) P( B) P( A B) 2. P( A) 1 P( A) 3. P( A | B) 4. P( A) P( A B) P( A B) 5. P( A B) P( A B) 1 6. P( A B) P( A) P( B) and P( A B) 0 if A and B are mutually exclusive 7. P( A B) P( A) P( B) and P( A | B) P( A) if A and B are independent P( A B) P( B) 28 SE Production Limited Venn diagram: 1. Region I: A B 2. 3. Region II: A B Region III: A B 4. Region IV: ( A B) Tree diagram: 1. Path I: P( A B) pq 2. Path I + Path III: P( B) P( A B) P( A B) pq (1 p)r Markov Chain with transition matrix T : 1. det(T I) : Characteristic polynomial of T 2. Solution(s) of det(T I) 0 : Eigenvalue(s) of T 3. v : Steady state probability vector, which is the eigenvector of T corresponding to the eigenvalue 1 4. v 0 : Initial state probability vector 5. v n Tn v 0 : State probability vector after n transitions 6. The column sum of T must be equal to 1 24 Discrete Probability Distributions Properties of a discrete random variable X : X x1 x2 … xn P( X x) P( X x1 ) P( X x2 ) … P( X xn ) 1. P( X x1 ) P( X x2 ) P( X xn ) 1 2. E( X ) x1P( X x1 ) x2 P( X x2 ) 3. E( X ) 0 if a fair game is considered xn P( X xn ) : Expected value of X 29 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics 25 Binomial Distribution Properties of a random variable X ~ B(n, p) following binomial distribution: 1. 2. Only two outcomes from every independent trial (Success and failure) n : Number of trials 3. p : Probability of success 4. X : Number of successes in n trials Formulae for binomial distribution: 2. n P( X r ) p r (1 p)n r for 0 r n , r r E( X ) np : Expected value of X 3. Var( X ) np(1 p) : Variance of X 1. 4. np(1 p) : Standard deviation of X 5. P( X r ) P( X r 1) 1 P( X r 1) 26 Poisson Distribution Properties of a random variable X ~ Po( ) following Poisson distribution: 1. The expected number of occurrences of an event is directly proportional to 2. the length of the time interval The numbers of occurrences of the event in different disjoint time intervals 3. 4. are independent : Mean number of occurrences of an event X : Number of occurrences of an event Formulae for Poisson distribution: 2. e r for r 0 , r r! E( X ) : Expected value of X 3. Var( X ) : Variance of X 4. 5. : Standard deviation of X 1. P( X r ) P( X r ) P( X r 1) 1 P( X r 1) 30 SE Production Limited 27 Normal Distribution Properties of a random variable X ~ N( , 2 ) following normal distribution: 5. : Mean : Standard deviation The mean, the median and the mode are the same The normal curve representing the distribution is a bell-shaped curve which is symmetric about the middle vertical line P( X ) P( X ) 0.5 6. The total area under the curve is 1 1. 2. 3. 4. 28 Linear Combinations of Variables Properties of linear transformations of independent random variables: 1. E(aX b) aE( X ) b 2. Var(aX b) a 2 Var( X ) 3. E(a1 X1 a2 X 2 4. Var(a1 X1 a2 X 2 an X n ) a1E( X1 ) a2E( X 2 ) an E( X n ) an X n ) a12 Var( X1 ) a22Var( X 2 ) an2Var( X n ) 29 Point Estimation Central limit theorem: 1. X i ~ N ( , 2 ) 2. X 3. 2 X ~ N , when n is sufficiently large n X1 X 2 n Xn : Sample mean 31 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics Properties of point estimation: n 1. 2 n 1 s (X X ) i 1 i n 1 2 : Sample variance n (X X ) 2 i 2. sn2 i 1 3. sn21 4. E( X ) X 5. E( sn21 ) 2 n n 2 sn n 1 30 Interval Estimation (1 )% confidence interval for population mean when the population variance 2 is known: X X2 Xn 1. : Sample mean X 1 n 2. , X z X z , where P Z z 2 n n 2 2 2 3. : Interval width 2z n 2 (1 )% confidence interval for population mean when the population variance 2 is unknown: X X2 Xn 1. : Sample mean X 1 n sn 1 s 2. , X t n 1 , where P X t X tn 1, n 1, n 1, 2 n n 2 2 2 s 3. 2t n 1 : Interval width n 1, n 2 32 SE Production Limited 31 Bivariate Analysis Correlations: Positive Strong 0.75 < r < 1 Moderate 0.5 < r < 0.75 Weak 0 < r < 0.5 No Negative r =0 Weak −0.5 < r < 0 Moderate −0.75 < r < −0.5 Strong −1 < r < −0.75 where r is the correlation coefficient Linear regression: = y ax + b : Regression line of y on x Correlation Coefficient for ranked data: rs : Spearman’s Rank Correlation Coefficient Coefficient of determination: R 2 : Coefficient of determination R 2 % of the variability of the data can be explained by the regression model Sum of square residuals: x x1 x2 … xn y y1 y2 … yn ŷ1 ŷ2 … yˆ n Predicted value of y = SS res n ∑ ( y − yˆ ) : Sum of square residuals i =1 i i 2 Non-linear regressions: 1. 2. 3. Quadratic regression Cubic regression Quartic regression 4. 5. Exponential regression Logarithmic regression 6. 7. Power regression Logistic regression 33 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics 32 Statistical Tests Hypothesis test: H 0 : Null hypothesis H1 : Alternative hypothesis C : Critical value in the hypothesis test : Significance level 2 test for independence for a contingency table with r rows and c columns: n rc : Total number of data Oi ( i 1, 2, , n ): Observed frequencies Ei ( i 1, 2, , n ): Expected frequencies v (r 1)(c 1) : Degree of freedom (Oi Ei )2 : 2 test statistic Ei i 1 n 2 calc H 0 : Two variables are independent H1 : Two variables are not independent 2 H 0 is rejected if calc C or the p -value is less than the significance level 2 H 0 is not rejected if calc C or the p -value is greater than the significance level 2 goodness of fit test for a contingency table with 1 row and c columns: v c 1 : Degree of freedom H 0 : The data follows an assigned distribution H1 : The data does not follow an assigned distribution 2 H 0 is rejected if calc C or the p -value is less than the significance level 2 H 0 is not rejected if calc C or the p -value is greater than the significance level Two sample t test: 1 , 2 : The population means of two groups of data H 0 : 1 2 H1 : 1 2 , 1 2 (for 1-tailed test), 1 2 (for 2-tailed test) H 0 is rejected if the p -value is less than the significance level H 0 is not rejected if the p -value is greater than the significance level 34 SE Production Limited More about 2 test for independence and 2 goodness of fit test: All expected frequencies Ei should be greater than 5 Z test when the population variance 2 is known: : Population mean H 0 : 0 H1 : 0 , 0 (for 1-tailed test), 0 (for 2-tailed test) H 0 is rejected if the p -value is less than the significance level H 0 is not rejected if the p -value is greater than the significance level One sample t test when the population variance 2 is unknown: : Population mean H 0 : 0 H1 : 0 , 0 (for 1-tailed test), 0 (for 2-tailed test) H 0 is rejected if the p -value is less than the significance level H 0 is not rejected if the p -value is greater than the significance level Paired t test: d x y : Difference between each pair of data from two variables x and y H 0 : d 0 H1 : d 0 , d 0 (for 1-tailed test), d 0 (for 2-tailed test) H 0 is rejected if the p -value is less than the significance level H 0 is not rejected if the p -value is greater than the significance level Test involving binomial distribution: X ~ B(n, p) H 0 : p p0 H1 : p p0 , p p0 x : Observed value of X P( X x) for H1 : p p0 or P( X x) for H1 : p p0 : p -value under X ~ B(n, p0 ) H 0 is rejected if the p -value is less than the significance level H 0 is not rejected if the p -value is greater than the significance level 35 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics Test involving Poisson distribution: X ~ Po( ) H 0 : 0 H1 : 0 , 0 x : Observed value of X P( X x) for H1 : 0 or P( X x) for H1 : 0 : p -value under X ~ Po(0 ) H 0 is rejected if the p -value is less than the significance level H 0 is not rejected if the p -value is greater than the significance level Test involving bivariate normal distribution: : Product moment correlation coefficient H0 : 0 H1 : 0 , 0 (for 1-tailed test), 0 (for 2-tailed test) H 0 is rejected if the p -value is less than the significance level H 0 is not rejected if the p -value is greater than the significance level Type I and type II errors: : Significance level P(Reject H 0 | H 0 is true) : Type I error P(Not reject H 0 | H 0 is not true) : Type II error 33 Paper 3 Analysis Nature of paper: Structured question Time allowed: 60 minutes Maximum mark: 55 marks Number of questions: 2 Mark range per question: 25 marks to 30 marks Weighting: 20% of the total mark 36 SE Production Limited Ways of assessing: 1. Identify a hypothesis test 2. State (a) a condition (b) (c) a reason an assumption 3. Write down (a) the value of a quantity (b) the formula of a quantity 4. Find (a) the value of a quantity (b) the formula of a quantity 5. Solve an equation 6. 7. Perform a hypothesis test Show (a) a quantity equals to a value 8. (b) the formula of a quantity Estimate the value of a quantity 9. 10. Predict the value of a quantity Sketch a graph 11. 12. Suggest an improvement Explain a reason 13. Describe a result 14. Verify (a) the value of a quantity 15. (b) the expression of a quantity Comment on (a) (b) the validity of an argument a statement 37 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics Notes 38 SE Production Limited 39 www.seprodstore.com Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics 40 SE Production Limited