Question

How do you use a calculator to solve each equation on the interval `(0 <= x < 2pi)` for `cos(x) = 0.6`?

Answer 1

Solve `cos x = 0.6`

Ans: `+- 53^@13`

Explanation:

By calculator:
cos x = 0.6 --> `x = 53^@13`.
Trig unit circle gives another arc x that has the same cos value -->
cos x = 0.6 --> x = - 53^@13.
Answer: `x = +- 53^@13`