24 March 2020 Sergiu Funieru The formula for sec (-a) [formula for the secant of minus a] +1 The formula for sec (-a) [formula for the secant of minus a] Have you seen this? +1
![The formula for sec (-a) [formula for the secant of minus a]](https://lunlun.com/wp-content/uploads/2020/03/The-formula-for-sec-a-formula-for-the-secant-of-minus-a.png "The formula for sec (-a) [formula for the secant of minus a]")