Practice Notation Overload in Math

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

Quick Recap

When the same symbol is used to mean different things in different contexts, requiring the reader to infer meaning from context.

The same word meaning different things in different conversations — context tells you which meaning applies, but this can trip up a reader who is new to the context.

Showing a random 20 of 50 problems.

Example 1

medium
The symbol n! uses '!' for factorial. Compute 4!.

Example 2

medium
In a matrix context, ∣A∣ for A=(3124) means the determinant. Compute it.

Example 3

hard
In abstract algebra, Z/nZ denotes the integers mod n. For n=5, how many distinct elements are in this set?

Example 4

medium
The symbol (a,b) can mean an open interval or an ordered pair. As a gcd, (8,12) means gcd⁡. Compute (8,12) in that sense.

Example 5

easy
What does f′(x) mean in calculus? For f(x)=x2, give f′(3).

Example 6

challenge
In tensor calculus, Tij vs Tij vs Tji all denote different things. What standard convention disambiguates them?

Example 7

challenge
In ank, what's the difference between k as an index and k as an exponent? Give an example where this distinction matters.

Example 8

easy
In the context {1,2,3}, what does {} mean?

Example 9

hard
In f(x)=x2, the parentheses denote function application. In (x+1)2, what do the parentheses denote? Compute when x=3.

Example 10

challenge
(nk) and C(n,k) both denote combinations, but 'nCr' on a calculator is the same. Compute (52).

Example 11

medium
The superscript in T−1 for a matrix means inverse, while AT means transpose. For A=(1234), give the top-left entry of AT.

Example 12

easy
The symbol ∣⋅∣ is used for absolute value of numbers and cardinality of sets. Evaluate: (a) ∣−3∣, (b) ∣{1,2,3}∣.

Example 13

medium
log⁡x can mean base-10, base-e, or base-2 depending on field. In CS texts, it usually means base what?

Example 14

medium
In the expression sin⁡2x, the superscript 2 means what? Compute sin⁡2(π/6).

Example 15

medium
The symbol ∗ can mean: (1) multiplication, (2) convolution, (3) a generic binary operation. For each usage, give one example context.

Example 16

challenge
Translate carefully: the statement '∣G∣=6 and G is generated by elements satisfying a3=e and b2=e.' What does each symbol mean?

Example 17

medium
Set-builder {x∈R∣x>0}: what does the ∣ mean?

Example 18

easy
In the integral ∫abf(x) dx, what does dx mean?

Example 19

medium
Decide what (2,5) means in each context: (i) coordinate plane; (ii) interval on the real line. For (ii), is 3 in the set?

Example 20

easy
In Rn, what does the superscript n mean?