![geometry - How can I calculate $\alpha=\arccos\left(-\frac{1}{4}\right)$ without using a calculator? - Mathematics Stack Exchange geometry - How can I calculate $\alpha=\arccos\left(-\frac{1}{4}\right)$ without using a calculator? - Mathematics Stack Exchange](https://i.stack.imgur.com/O23Ia.png)
geometry - How can I calculate $\alpha=\arccos\left(-\frac{1}{4}\right)$ without using a calculator? - Mathematics Stack Exchange
SOLUTION: Evaluate without calculator. Variables are positive numbers. I've been trying but can't figure out what arcsin and arctan are. Thanks! cos ( arcsin 4/5 - arctan 2)
How to make sin-1 on a calculator that just has a plain sin button like the one on Windows 10 - Quora
![Evaluate the expression without using a calculator. \textrm{arcsin }\frac{\sqrt{2}}{2} | Homework.Study.com Evaluate the expression without using a calculator. \textrm{arcsin }\frac{\sqrt{2}}{2} | Homework.Study.com](https://homework.study.com/cimages/multimages/16/45_45_90_tri6977614707527725529.png)