Read the first worked example with the solution open so the structure is clear.
Try the practice problems before revealing each solution.
Use the related concepts and background knowledge badges if you feel stuck.
What to Focus On
Core idea:A concept network is the web linking math ideas by dependence, analogy, and application.
Common stuck point:The procedure for concept networks is the easy part; the trap is studying topics as isolated islands. Asking "Am I mapping ALL kinds of links (dependence, analogy, application) among ideas, not just the prerequisite chain?" first is what keeps a correct-looking calculation from being attached to the wrong concept.
Sense of Study hint:Ask: Am I mapping ALL kinds of links (dependence, analogy, application) among ideas, not just the prerequisite chain?
Worked Examples
Example 1
easy
Draw (describe) the concept network connecting: set, subset, union, intersection, complement, and De Morgan's laws.
First layer: 'subset', 'union', 'intersection', 'complement' — all defined in terms of sets and their elements.
3
Second layer: 'De Morgan's laws' — connect complement with union and intersection via the identities (A∪B)′=A′∩B′ and (A∩B)′=A′∪B′.
4
Edges: set → subset (membership check), set → union/intersection (binary operations), set → complement (unary operation), {union, intersection, complement} → De Morgan's laws (structural relationship).
A concept network shows how mathematical ideas relate and depend on each other. Building such networks helps learners see mathematics as a coherent structure rather than isolated facts.
Example 2
medium
Identify three connections between set theory and logic in the concept network. For each, give the corresponding pair of concepts.
Example 3
easy
Differentiation undoes integration (dxd∫axf=f). Name the network relationship and apply it to f(x)=x3 to find dxd∫0xt3dt.
Example 4
medium
Function composition and matrix multiplication encode 'do one transformation then another.' If A rotates by 90° and B reflects across the x-axis, the product BA corresponds to which composition: first do A or first do B?
Example 5
hard
Linear systems, matrix equations, and intersection of lines are the same node. Solve {x+y=5x−y=1.
Example 6
challenge
Information, entropy, and probability share a node via H=−∑pilog2pi. Compute H for a fair coin.
Practice Problems
Try these problems on your own first, then open the solution to compare your method.
Example 1
easy
Name three concepts that are directly connected to 'mathematical induction' in the concept network and explain each connection.
Example 2
medium
Contrapositive, conditional, and proof by contradiction are three connected concepts. Describe the network: how does each relate to the others?
Example 3
easy
Slope of a line, rate of change, and the derivative all express the same core idea. What is that shared idea linking them in the concept network?
Example 4
easy
The Pythagorean theorem connects to the distance formula. What does the distance formula essentially compute?
Example 5
easy
Multiplication is repeated addition; exponentiation is repeated multiplication. What operation is exponentiation built on in this chain?
Example 6
easy
Fractions, decimals, and percentages can all represent 1/2. What single concept do they all express?
Example 7
easy
Linearity (output scales with input) appears in algebra (y = mx), calculus (derivatives), and matrices. What property is reappearing across these areas?
Example 8
easy
Solving 2x = 6 and the inverse operation of multiplication are linked. Division undoes multiplication. What is this relationship called?
Example 9
easy
Probability and area are connected: the chance a dart lands in a region equals that region's area fraction. What concept bridges them?
Example 10
easy
Adding fractions requires a common denominator; adding like terms in algebra requires the same variable. What shared principle connects these?
Example 11
medium
In a concept network, 'functions' connects to graphs, equations, calculus, and sequences. If a student strengthens 'functions,' which network property explains why many other topics improve at once?
Example 12
medium
A student learns the binomial theorem, Pascal's triangle, and combinations separately. Show they are the same network idea by stating what the coefficient C(4,2) equals in Pascal's triangle and in (a+b)^4.
Example 13
medium
Exponential growth appears in compound interest, population models, and radioactive decay. Identify the single equation form they share and what differs between growth and decay.
Example 14
medium
A network has concepts as nodes and 'is-used-to-prove' as edges. If A proves B, B proves C, and A proves C directly, what does the direct edge A->C represent, and is it redundant for connectivity?
Example 15
medium
The mean, the balance point of a distribution, and the center of mass in physics are the same idea. Compute the balance point of masses 2 at x=0 and 4 at x=3 to confirm the link.
Example 16
medium
Matrix multiplication, function composition, and 'do one transformation then another' are connected. If f doubles and g adds 1, what is the single rule for (g after f)(x)?
Example 17
challenge
In a concept-dependency DAG, define 'centrality' of a node as the number of shortest paths (between other nodes) passing through it. For the path graph A-B-C-D-E (each adjacent pair connected), argue which node has the highest betweenness and why it is a network bottleneck.
Example 18
challenge
Show that the identities sin^2 + cos^2 = 1, the Pythagorean theorem, and the equation of a unit circle x^2 + y^2 = 1 are the same network node by mapping (x, y) on the unit circle to (cos t, sin t).
Example 19
challenge
A knowledge network is 'fragile' if removing one node disconnects many others. Given a star graph with center H connected to 6 leaves, compute how many pairwise connections are lost if H is removed, and explain the lesson for learning.
Example 20
medium
Logarithms and exponentials are inverse functions; so are squaring and square root. State the network relationship and what log(10^x) simplifies to.
Example 21
medium
The quadratic formula, completing the square, and the vertex form of a parabola are connected. What does completing the square on x^2 + 6x produce, linking to the vertex?
Example 22
medium
Vectors, complex numbers, and points in the plane all represent (a, b). Show the link by stating what the complex number 3 + 4i corresponds to as a point and its distance from the origin.
Example 23
easy
Vectors (a,b) and complex numbers a+bi are isomorphic as 2D objects. Give the magnitude of 4+3i.
Example 24
easy
Graphs of y=2x and tables doubling input both express linear scaling. What is the slope of y=2x?
Example 25
medium
Geometric series, repeating decimals, and infinite limits connect via the formula ∑n=0∞arn=1−ra, ∣r∣<1. Evaluate 0.3.
Example 26
medium
The slope between two points and the average rate of change are the same idea. For f(x)=x2 on [1,3], compute it.
Example 27
medium
Logical AND and set intersection are linked. If A={1,2,3} and B={2,3,4}, give A∩B.
Example 28
medium
Median is the 50th percentile; the median splits area under a density in half. For the data 1,3,5,7,9, give the median.
Example 29
medium
Dot product and projection are connected. For u=(3,4) and v=(1,0), give u⋅v.
Example 30
medium
Polar coordinates and complex numbers in modulus-argument form are linked. Write 1+i in polar form (r,θ).
Example 31
medium
GCD and the Euclidean algorithm rely on the same divisibility network. Compute gcd(48,18).
Example 32
medium
Symmetry in algebra (even/odd functions) and symmetry in geometry (mirror/rotation) share a network node. f(x)=x4 has which kind of symmetry?
Example 33
medium
Sequences, functions of n, and discrete dynamical systems are linked. For an=2n, give a5.
Example 34
hard
Determinants, area scaling, and invertibility are network-connected. A 2x2 matrix has det=0. What does this say about invertibility?
Example 35
hard
Modular arithmetic, clock arithmetic, and group theory share the node Z/n. Compute 7+8(mod12).
Example 36
hard
Areas under curves and antiderivatives are linked by the Fundamental Theorem of Calculus. Find ∫02xdx.
Example 37
hard
Conic sections (circle, ellipse, parabola, hyperbola) all come from slicing a cone. Identify the conic of x2+y2=9.
Example 38
hard
Probability and integration are linked via density functions. For density f(x)=2x on [0,1], give P(X≤0.5).
Example 39
hard
Exponentials, logarithms, and inverse functions share a node. Solve 2x=32.
Example 40
challenge
Eigenvalues unify stretching factors, repeated dynamics, and stability. For A=(2003), list the eigenvalues.