Find each value. Write angle measures in degrees and radians. 1. ANSWER: 30°; 2. ANSWER: −60°; 3. Arccos(
In[2397]:= Needs["FunctionApproximations`"] In[2398]:= Plot[ArcCos[x], {x, −1, +1 }, PlotRange → {0, π}] Plot[Arc
![How can I calculate $\alpha=\arccos\left(-\frac{1}{4}\right)$ without using a calculator? - Mathematics Stack Exchange 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)
How can I calculate $\alpha=\arccos\left(-\frac{1}{4}\right)$ without using a calculator? - Mathematics Stack Exchange
![How can I calculate $\alpha=\arccos\left(-\frac{1}{4}\right)$ without using a calculator? - Mathematics Stack Exchange How can I calculate $\alpha=\arccos\left(-\frac{1}{4}\right)$ without using a calculator? - Mathematics Stack Exchange](https://i.stack.imgur.com/ZhHAx.png)