Nielsen and Chuang: Demonstration of equation 2.12
93550
How to find the matrix representation of an operator from its action on a basis?
84465
Off-center impulse equations
62484
Proving Hartshorne's Exercise I-1.9 by using exercise I-1.8
23119
An application of Jensen's Inequality
32420
A complete orthonormal system contained in a dense sub-space.
41534
A system of logarithmic equations with parameters
35281
$1992$ IMO Functional Equation problem
2743
Dot Product and Cross Product: Solving a set of Simultaneous Vector Equations
104176
$15x\equiv 20 \pmod{88}$ Euclid's algorithm
82823
Attractive Boxed Equations
36713
Solving multiple congruences by CRT = Chinese Remainder Theorem
39969
Algorithms for computing multiplicative order modulo $n$
132595
$\sup_{0 \leq M \leq I_{\mathcal{H}_1}} \frac{\operatorname{Tr}[\rho M]}{\operatorname{Tr}[\sigma M]}$ satisfies Data Processing Inequality
17267
Interchanging the order of differentiation and summation
84879
Solving infinite sums with primes.
153692
Generating and solving recurrence relations
32350
Compilation of proofs for the summation of natural squares and cubes