A prettier way of on how to prove the identities
34049
How can I understand and prove the "sum and difference formulas" in trigonometry?
137369
Inductive proof of gcd Bezout identity (from Apostol: Math, Analysis 2ed)
65983
Combinatorial proof of binomial coefficient summation identity
109649
idempotents acting as local identities
125263
How to crack the proof
57215
Stuck on formal proofs. Not sure how to continue
89552
proving combinatorics identity - $\sum_{k=0}^m{n-k \choose m-k}={n+1 \choose m}$
146822
Tips for writing proofs
103504
Weird $3^n$ in an identity to be combinatorially proved
115663
Proving an isomorphism using the isomorphism theorems
20346
'Algebraic' way to prove the boolean identity $a + \overline{a}*b = a + b$
76635
Proof through combinatorial argument
126114
Adding line by line comments to math proofs
108873
How would one be able to prove mathematically that $1+1 = 2$?
115435
Induction: prove using congruences
15100
Proving the identity $\sum_{k=1}^n {k^3} = \big(\sum_{k=1}^n k\big)^2$ without induction
18301
Proof by Induction involving Inequality and Factorials as denominators