- The Epistle to the Philippians is a Pauline epistle of the New Testament of the Christian Bible. The epistle is attributed to Paul the Apostle and Timothy is named with him as co-author or co-sender. The letter is addressed to the Christian church in Philippi. Paul, Timothy, Silas (and perhaps Luke) first visited Philippi in Greece (Macedonia) during Paul’s second missionary journey from Antioch, which occurred between approximately 49 and 51 AD. In the account of his visit in the Acts of the Apostles, Paul and Silas are accused of “disturbing the city”.
- Euler’s formula (Wikipedia)
Euler’s formula, named after Leonhard Euler, is a mathematical formula in complex analysis that establishes the fundamental relationship between the trigonometric functions and the complex exponential function. Euler’s formula states that, for any real number x, one has eix = cos x + i sin x, where e is the base of the natural logarithm, i is the imaginary unit, and cos and sin are the trigonometric functions cosine and sine respectively. This complex exponential function is sometimes denoted cis x (“cosine plus i sine”). The formula is still valid if x is a complex number, and is also called Euler’s formula in this more general case.