Practice Analogical Reasoning in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

Drawing conclusions about a new situation by recognizing its structural similarity to a better-understood situation.

This is like that, so maybe what works there will work here.

Showing a random 20 of 50 problems.

Example 1

medium
A derivative is like a speedometer (instantaneous rate). For position s(t)=t2s(t)=t^2, the 'speedometer' reading at t=4t=4 is s(4)s'(4). Compute it.

Example 2

hard
By analogy with arithmetic mean and geometric mean of two numbers, identify the harmonic mean.

Example 3

medium
Even/odd is to integers as ___ is to functions.

Example 4

easy
Derivative is to slope as integral is to ___?

Example 5

easy
The analogy between sets and logic: ABA \cup B (union) corresponds to pqp \lor q (OR), and ABA \cap B (intersection) corresponds to pqp \land q (AND). Use this analogy to conjecture a set version of De Morgan's law ¬(pq)¬p¬q\neg(p \lor q) \equiv \neg p \land \neg q.

Example 6

hard
Vector space is to basis as field is to ___? Give the most direct analog.

Example 7

challenge
Analogy is not proof: two systems behaving alike does not transfer theorems. But a valid structural analogy: complex multiplication adds angles. Multiplying numbers at angles 30°30° and 40°40° gives a result at what angle?

Example 8

challenge
Map-is-not-the-territory: a model approximates reality. Linear approximation of f(x)=x2f(x)=x^2 near x=3x=3 uses the tangent line y=9+6(x3)y=9+6(x-3). Estimate f(3.1)f(3.1) with it.

Example 9

easy
Map is to territory as model is to ___? Both are simplified stand-ins. A model represents reality. If a map scale is 1:10001:1000, a 55 cm map distance is how many cm in reality?

Example 10

medium
Sum is to integral as product is to ___? Express the analogous operator name and write the symbol.

Example 11

medium
The Pythagorean theorem a2+b2=c2a^2+b^2=c^2 for right triangles in the plane has a 3D analog for the diagonal of a box with edges a,b,ca,b,c. State it.

Example 12

easy
Logarithm is to multiplication as ___ is to addition: an inverse-flattening tool. Since logs turn products to sums, log10(10×100)\log_{10}(10\times100) equals which sum's value?

Example 13

medium
In arithmetic, the number 00 is the identity for addition (a+0=aa+0=a). By analogy, identify the identity element for set union and for set intersection.

Example 14

hard
Use the analogy: rate is to distance as marginal cost is to ___? Use a one-sentence justification.

Example 15

medium
Arithmetic has addition and multiplication. By analogy, what operations does set theory have, and what arithmetic laws transfer? Identify two laws that hold and one that does not.

Example 16

medium
Probability is like a slice of a pie (fraction of the whole). If an event covers 90°90° of a 360°360° pie, its probability is?

Example 17

easy
Circle is to π\pi as ___? The circle's circumference-to-diameter ratio is π\pi. To 11 decimal, give π\pi.

Example 18

medium
Numerator is to a fraction as dividend is to division. In 124\frac{12}{4}, the numerator 1212 plays the dividend role; give the quotient.

Example 19

easy
Equation is to equals sign as inequality is to ___?

Example 20

easy
In arithmetic, subtraction undoes addition. In linear algebra, what undoes adding a vector v\vec v?