Practice Generalization in Math

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

Quick Recap

The process of extending a specific result or pattern to hold for a broader class of objects or situations.

Does this pattern work more generally? Can we remove restrictions?

Showing a random 20 of 50 problems.

Example 1

medium
50=15^0 = 1 and 70=17^0 = 1. Generalize a0a^0 and state the exception.

Example 2

easy
Specific: 0+7=70 + 7 = 7, 0+11=110 + 11 = 11. Generalize: what is 0+n0 + n?

Example 3

easy
23โ‹…24=272^3 \cdot 2^4 = 2^7 and 52โ‹…56=585^2 \cdot 5^6 = 5^8. Generalize the exponent rule.

Example 4

easy
A right triangle has legs 33 and 44 with hypotenuse 55. Generalize to legs aa and bb with hypotenuse cc.

Example 5

medium
(xโˆ’1)(x+1)=x2โˆ’1(x-1)(x+1) = x^2 - 1. Generalize to a difference of two squares.

Example 6

medium
2โ‹…3=62\cdot3=6 shares no structure issue, but generalize: for primes pp, is p2p^2 ever even? Decide and generalize.

Example 7

medium
The formula 1+2+โ‹ฏ+n=n(n+1)21+2+\cdots+n = \frac{n(n+1)}{2} holds for n=1,2,3n=1,2,3. State how you would generalise this claim to all positive integers and what technique would be used.

Example 8

hard
(42)=(42)\binom{4}{2} = \binom{4}{2} (trivial). Generalize the symmetry of binomials.

Example 9

easy
From 12+12=1\frac{1}{2}+\frac{1}{2}=1, generalize: what is 1n\frac{1}{n} added to itself nn times?

Example 10

medium
gcdโก(6,4)=2\gcd(6,4) = 2, gcdโก(15,10)=5\gcd(15,10) = 5, gcdโก(8,12)=4\gcd(8, 12) = 4. Generalize: what is gcdโก(a,b)\gcd(a, b) in terms of common factors?

Example 11

easy
Specific: 3ร—5=153 \times 5 = 15 (odd ร—\times odd = odd). Generalise: prove that the product of any two odd integers is odd.

Example 12

medium
sinโก30ยฐ=1/2\sin 30ยฐ = 1/2, sinโก150ยฐ=1/2\sin 150ยฐ = 1/2. Generalize: when does sinโกฮธ=1/2\sin\theta = 1/2?

Example 13

hard
1+r+r2=1โˆ’r31โˆ’r1 + r + r^2 = \frac{1 - r^3}{1 - r} for rโ‰ 1r \ne 1. Generalize the finite geometric sum.

Example 14

medium
1โ‹…2=21\cdot2=2, 2โ‹…3=62\cdot3=6, 3โ‹…4=123\cdot4=12. Generalize the product of two consecutive integers n(n+1)n(n+1) and state its parity.

Example 15

hard
โˆ‘k=0n(nk)=2n\sum_{k=0}^{n}\binom{n}{k} = 2^n holds for small nn. Justify the generalization combinatorially.

Example 16

easy
Specific: 5โˆ’5=05 - 5 = 0, 7โˆ’7=07 - 7 = 0. Generalize to any real aa.

Example 17

medium
(42)=6\binom{4}{2} = 6, (52)=10\binom{5}{2} = 10, (62)=15\binom{6}{2} = 15. Generalize (n2)\binom{n}{2}.

Example 18

easy
The sum of interior angles is 180โˆ˜180^\circ for a triangle and 360โˆ˜360^\circ for a quadrilateral. Generalize to an nn-gon.

Example 19

easy
Specific: 3+(4+5)=(3+4)+53 + (4 + 5) = (3 + 4) + 5. Generalize this to any a,b,ca, b, c.

Example 20

medium
12=11^2 = 1, 12+22=51^2 + 2^2 = 5, 12+22+32=141^2 + 2^2 + 3^2 = 14. Find a closed formula for โˆ‘k=1nk2\sum_{k=1}^{n} k^2.